Accepted
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Abstract +
The growing demands of high-speed imaging, aerospace, and optical communication have driven intensive research on broadband photodetectors with high sensitivity and fast response. Twodimensional (2D) materials, featuring atomic-scale thickness, tunable bandgaps, and excellent carrier transport properties, are regarded as ideal candidates for next-generation optoelectronics. However, their limited light absorption and intrinsic recombination losses remain key challenges. This review provides an overview of recent progress in 2Dmaterial-based broadband photodetectors. First, the fundamental optoelectronic properties of 2D materials, including bandgap modulation, carrier dynamics, and light - matter interactions, are discussed to clarify their broadband detection potential. Representative material systems - such as narrow-bandgap semiconductors, 2D topological materials, and perovskites - are summarized, demonstrating detection capabilities spanning from ultraviolet to mid-infrared regions. To overcome intrinsic limitations, four optimization strategies are highlighted: heterostructure engineering for efficient charge separation and extended spectral response; defect engineering to introduce mid-gap states and enhance sub-bandgap absorption; optical field enhancement through plasmonic nanostructures and optical cavities to improve responsivity; and strain engineering for reversible band structure tuning, particularly suited for flexible devices. These strategies have enabled remarkable improvements in responsivity, detectivity, and bandwidth, with some devices achieving ultrabroadband detection and multifunctionality. In summary, 2D materials and their hybrids have shown great promise for broadband photodetection, with advances spanning from material innovation to device architecture optimization. The reviewed strategies - heterostructure integration, defect modulation, optical field enhancement, and strain engineering - collectively demonstrate the diverse pathways to overcome intrinsic limitations and boost device performance. Looking forward, the rational combination of these approaches is expected to further expand the detection window, improve sensitivity, and enable multifunctional operation, thereby paving the way toward nextgeneration broadband photodetectors with versatile applications in imaging, sensing, and optoelectronic systems
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Abstract +
Diagnostics of combustion flow fields in aeroengines, scramjets, and related systems play a crucial role in understanding combustion mechanisms, assessing combustion stability and performance, and represent a major challenge in the development of advanced propulsion technologies. Among the non-intrusive diagnostic approaches, laser absorption spectroscopy has become one of the most representative techniques. In particular, tunable diode laser absorption spectroscopy (TDLAS) offers advantages such as a compact system architecture, ease of miniaturization, strong environmental adaptability, and the capability of simultaneous temperature and concentration measurements. By employing multiple laser beams intersecting at different angles and collecting absorption spectra along various paths, the two-dimensional distribution of flow-field parameters can be reconstructed using computed tomography (CT) algorithms.
However, conventional nonlinear tomographic algorithms based on polynomial models encounter difficulties when reconstructing flow fields with steep gradients. To address this issue, we propose a hybrid reconstruction method that integrates a regional weighting mechanism. In this framework, the polynomial model is combined with a Gaussian radial basis function (RBF) model, and a regional weight matrix is iteratively updated in an adaptive manner. The regional weight matrix is determined by introducing perturbations into the current temperature field and jointly considering its temperature gradient. This design allows the hybrid model to capture global features while enhancing its ability to resolve local details. In addition, a regional weight regularization term is incorporated into the residual function to further improve reconstruction accuracy.
To validate the proposed approach, numerical simulations were conducted on three representative combustion field distributions, with comparisons against polynomial model, RBF model, and traditional algebraic reconstruction technique (ART) algorithms. Results demonstrate that the hybrid model achieves higher representational capability and reconstruction accuracy, with maximum temperature and concentration errors reduced to 3.31% and 7.13% (for the Top-Hat case), respectively. A scanning TDLAS measurement platform and a thermocouple measurement platform were built on a standard McKenna burner to experimentally verify the method. The reconstructed distributions exhibit good consistency with the experimental results, with a deviation of only 10 K between the reconstructed central temperature at 1800 K and the thermocouple measurement. These findings verify the effectiveness of the proposed method and highlight its potential as a reliable tool for combustion field diagnostics in propulsion systems.
However, conventional nonlinear tomographic algorithms based on polynomial models encounter difficulties when reconstructing flow fields with steep gradients. To address this issue, we propose a hybrid reconstruction method that integrates a regional weighting mechanism. In this framework, the polynomial model is combined with a Gaussian radial basis function (RBF) model, and a regional weight matrix is iteratively updated in an adaptive manner. The regional weight matrix is determined by introducing perturbations into the current temperature field and jointly considering its temperature gradient. This design allows the hybrid model to capture global features while enhancing its ability to resolve local details. In addition, a regional weight regularization term is incorporated into the residual function to further improve reconstruction accuracy.
To validate the proposed approach, numerical simulations were conducted on three representative combustion field distributions, with comparisons against polynomial model, RBF model, and traditional algebraic reconstruction technique (ART) algorithms. Results demonstrate that the hybrid model achieves higher representational capability and reconstruction accuracy, with maximum temperature and concentration errors reduced to 3.31% and 7.13% (for the Top-Hat case), respectively. A scanning TDLAS measurement platform and a thermocouple measurement platform were built on a standard McKenna burner to experimentally verify the method. The reconstructed distributions exhibit good consistency with the experimental results, with a deviation of only 10 K between the reconstructed central temperature at 1800 K and the thermocouple measurement. These findings verify the effectiveness of the proposed method and highlight its potential as a reliable tool for combustion field diagnostics in propulsion systems.
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Abstract +
HfOX memristors have emerged as one of the most promising candidates for next-generation non-volatile memory due to their low operating voltage, excellent endurance, and cycling characteristics. However, the randomness in the formation and rupture of oxygen vacancy conductive filaments within HfOX thin films leads to a relatively dispersed threshold voltage distribution and poor stability. Therefore, improving the stability of HfOX devices by modulating oxygen vacancies is of significant research importance. In this study, three groups of W/HfOX/Pt devices were prepared using magnetron sputtering with argon-to-oxygen ratios of 30:20, 40:10 and 45:5, respectively. XPS results indicated that the 45:5 device has the highest oxygen vacancy concentration(25.59%). All three groups exhibited bipolar resistive switching behavior. Among the three W/HfOX/Pt devices, the device with argon-to-oxygen ratio of 45:5 demonstrated the best overall performance: over 200 I-V cycles, a switching ratio of ~103, excellent data retention within 104 seconds, and a concentrated threshold voltage distribution. Analysis of the conduction mechanisms revealed that the device follows a space-charge-limited current (SCLC) mechanism in the high-resistance state and exhibits Ohmic conduction behavior in the low-resistance state. In the initial state, there is a high density of oxygen vacancies near the nucleation region of the conductive filament, which shortens the effective migration path of oxygen vacancies. Under an applied electric field, negatively charged oxygen ions migrate toward the top electrode, while oxygen vacancies gradually accumulate from the bottom electrode to the top electrode, leading to the formation of continuous conductive filaments. A higher oxygen vacancy concentration facilitates the development of robust and structurally more stable conductive filaments, thereby enhancing the uniformity of resistive switching and device reliability. This study reveals the critical role of oxygen vacancy modulation in the performance of HfOX memristors and provides an effective pathway for developing high-performance and highly reliable resistive random-access memory.
Abstract +
This study systematically investigates the bouncing behavior and dynamics of microbubbles under ultrasound excitation within a rigid capillary. It aims to provide quantitative insights into their oscillation characteristics, migration trajectories, and phase modulation mechanisms for applications in microfluidics, contrast-enhanced ultrasound imaging, and controlled drug delivery. A high-speed imaging system was employed to track the motion of single-, double-, and triple-bubble systems in a viscoelastic medium inside a capillary with a 0.5 mm inner diameter. Under a 28 kHz ultrasound field, bubble dynamics were captured at 100,000 frames per second. Image processing techniques, including dynamic threshold segmentation and morphological operations, were applied to extract bubble contours and centroid trajectories. Spectral analysis via Fast Fourier Transform (FFT) was performed to identify oscillation frequencies and modulation characteristics. Experimental results showed that a single bubble exhibits periodic lateral migration with oscillation frequency slightly below the driving frequency, alongside an asymmetric sideband distribution in its spectrum. In the two-bubble system, five distinct dynamic stages were identified: initial suppression, accelerated migration, interaction dominance, position exchange, and a secondary approach to the wall. The bubbles oscillated at a common dominant frequency of 27.32 kHz but maintained phase difference. Modulation sidebands of approximately 0.3 kHz were observed, indicating nonlinear coupling. The three-bubble system exhibited more complex spatiotemporal evolution, including sequential migration and transitions between triangular and mirror-symmetric configurations. A notable sideband at 0.1 kHz suggested that multi-bubble synergy enhances nonlinear behavior. The tube diameter and fluid viscosity were found to influence the bouncing period through added mass effects and viscous energy dissipation, respectively. The period increased significantly with decreasing tube diameter and decreased with reducing fluid viscosity. Theoretical modeling incorporated the mirror bubble effect into the coupled Keller-Miksis equations to account for wall confinement, successfully simulating the oscillation and translation of confined microbubbles. Numerical analysis further indicated that interbubble distance, wall proximity, and medium viscosity modulate the system's dynamics. Specifically, the bubble resonance frequency is regulated by inter-bubble distance and wall confinement. The two-bubble system exhibits both in-phase and out-of-phase modes, with the latter being more sensitive to distance variations. Near the wall, the oscillation frequency decreases, and the phase difference attenuation accelerates. Increased medium viscosity weakens the phase coupling between bubbles, an effect particularly pronounced for smaller bubbles. This study not only enhances the understanding of multi-bubble synergistic effects in confined spaces but also provides a theoretical foundation and technical reference for optimizing ultrasound contrast agents, designing microfluidic devices, and developing targeted therapies in biomedicine.
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Abstract +
Vortex dynamics in Bose-Einstein condensates (BECs) are crucial for understanding quantum coherence, superfluidity, and topological phenomena. In this work, we investigate the influence of barrier parameters in a rotating double-well potential on the formation and evolution of hidden vortices, aiming to elucidate the regulatory mechanisms of barrier width and height on vortex dynamics. By numerically solving the dissipative Gross-Pitaevskii equation for a two-dimensional BEC system confined strongly along the z-axis, we analyze the density distribution, phase distribution, vortex number, and average angular momentum under varying barrier widths and heights. The results show that increasing barrier width significantly promote the formation of hidden vortices, with the total number of visible and hidden vortices still satisfying the Feynman rule. For larger barrier widths, hidden vortices exhibite an oscillatory distribution due to enhanced vortex interactions, as shown in Fig. (a) with vortices marked by red dots. In contrast, barrier height has a limited impact on hidden vortex numbers when above a critical threshold (i.e., the height sufficient to completely separate the condensate), but below this critical threshold, hidden vortex cores become visible, reducing the threshold for vortex formation. A particularly striking finding is the efficacy of a temporary barrier strategy: by reducing V0 from 4ħωx to 0 within a rotating double-well trap, stable vortex states with four visible vortices are generated at Ω= 0.5ωx, as shown in Fig. (b). Under the same parameter conditions, it is impossible to generate a stable state containing vortices at the same Ω by directly using the rotating harmonic trap. In other words, a temporary barrier within a rotating harmonic trap effectively introduced phase singularities, facilitating stable vortex states at lower rotation frequencies than those required in a purely harmonic trap. These findings demonstrate that precise tuning of barrier parameters enables effective control of vortex states, offering theoretical guidance for experimental observation of hidden vortices and advancing the understanding of quantum vortex dynamics.
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Abstract +
As China's lunar exploration program advances steadily from the landmark orbiting missions of Chang'e-1 to the historic sample-return feats of Chang'e-5 and the groundbreaking far-side landing of Chang'e-4, the nation has entered a critical phase of deepening lunar exploration, including preparations for crewed lunar missions. Amid these ambitious endeavors, identifying and mitigating potential operational risks is paramount to ensuring mission success. This paper focuses on a critical hazard specific to China's lunar surface exploration efforts: the frictional charging and discharging phenomenon between lunar rover wheels and lunar dust, a factor with significant implications for astronaut safety and the reliability of onboard electronic systems.
Lunar surface missions will face the risk of triboelectric charging and discharging resulting from friction between lunar rover wheels and lunar dust. Preliminary theoretical studies indicate that metal wheels may become charged to a level of approximately -5000 volts, with discharge pulse currents reaching an order of magnitude of 0.1 amperes, posing a severe threat to astronaut safety and the normal operation of device circuits.
This paper employs ground-based experimental methods to investigate the triboelectric charging and discharging risks of lunar rover wheels in vacuum and simulated solar wind plasma environments. The research findings are as follows:
In a vacuum environment: When an aluminum alloy lunar rover wheel (136 mm in diameter) travels on a lunar dust layer at a speed of 0.003 m/s, it rapidly charges to a positive potential of several hundred volts. Discharge breakdown occurs when the wheel travels approximately 20 meters and reaches a potential of 550 volts. At this point, the captured discharge current pulse amplitude can reach 1.5 amperes, with a pulse duration of about 100 nanoseconds. Increasing the friction frequency significantly accelerates the charging rate and leads to more frequent discharges.
In a simulated solar wind plasma environment: When the wheel travels at 0.003 m/s, the combined effect of the environment and friction results in a negative charging potential. After reaching equilibrium, the potential stabilizes at approximately -830 volts, and discharges occur more frequently than in a vacuum environment. Discharge breakdown takes place when the wheel travels just 8.5 meters, with the discharge current pulse amplitude reaching up to 0.3 amperes and a pulse duration of 100 nanoseconds.
These discharge pulses cause electromagnetic interference to linear circuits, leading to abnormal output of voltage signals in follow-up mode. The abnormal signals have an amplitude on the order of 10 volts and a duration of 29 microseconds.
This study confirms that the risk of triboelectric charging and discharging in lunar rovers is relatively high. While theoretical models predict that the Lunar Roving Vehicle (LRV) would experience rapid dissipation of triboelectric charges (with no charging/discharging risk) when operating at 0.03 m/s, the experiments show that even at a slow speed of 0.003 m/s, the wheels still accumulate charges and experience frequent discharge breakdowns. The discharge pulse amplitude can reach the order of 1 ampere, and significant electromagnetic interference is caused to nearby circuits. Clearly, theoretical models underestimate the risk of triboelectric charging and discharging in lunar surface environments. It is recommended that subsequent engineering missions pay close attention to this issue and further evaluate the extent of its hazards.
Lunar surface missions will face the risk of triboelectric charging and discharging resulting from friction between lunar rover wheels and lunar dust. Preliminary theoretical studies indicate that metal wheels may become charged to a level of approximately -5000 volts, with discharge pulse currents reaching an order of magnitude of 0.1 amperes, posing a severe threat to astronaut safety and the normal operation of device circuits.
This paper employs ground-based experimental methods to investigate the triboelectric charging and discharging risks of lunar rover wheels in vacuum and simulated solar wind plasma environments. The research findings are as follows:
In a vacuum environment: When an aluminum alloy lunar rover wheel (136 mm in diameter) travels on a lunar dust layer at a speed of 0.003 m/s, it rapidly charges to a positive potential of several hundred volts. Discharge breakdown occurs when the wheel travels approximately 20 meters and reaches a potential of 550 volts. At this point, the captured discharge current pulse amplitude can reach 1.5 amperes, with a pulse duration of about 100 nanoseconds. Increasing the friction frequency significantly accelerates the charging rate and leads to more frequent discharges.
In a simulated solar wind plasma environment: When the wheel travels at 0.003 m/s, the combined effect of the environment and friction results in a negative charging potential. After reaching equilibrium, the potential stabilizes at approximately -830 volts, and discharges occur more frequently than in a vacuum environment. Discharge breakdown takes place when the wheel travels just 8.5 meters, with the discharge current pulse amplitude reaching up to 0.3 amperes and a pulse duration of 100 nanoseconds.
These discharge pulses cause electromagnetic interference to linear circuits, leading to abnormal output of voltage signals in follow-up mode. The abnormal signals have an amplitude on the order of 10 volts and a duration of 29 microseconds.
This study confirms that the risk of triboelectric charging and discharging in lunar rovers is relatively high. While theoretical models predict that the Lunar Roving Vehicle (LRV) would experience rapid dissipation of triboelectric charges (with no charging/discharging risk) when operating at 0.03 m/s, the experiments show that even at a slow speed of 0.003 m/s, the wheels still accumulate charges and experience frequent discharge breakdowns. The discharge pulse amplitude can reach the order of 1 ampere, and significant electromagnetic interference is caused to nearby circuits. Clearly, theoretical models underestimate the risk of triboelectric charging and discharging in lunar surface environments. It is recommended that subsequent engineering missions pay close attention to this issue and further evaluate the extent of its hazards.
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Abstract +
Infinite-layer nickelates, obtained by removing the apical oxygen from perovskite precursors, are the first nickelate system to exhibit superconductivity and provide a platform for exploring unconventional superconductivity. Although the traditional CaH2 sealed-tube reduction method is simple and effective, it is an ex-situ process that tends to cause surface contamination or degradation, making it unsuitable for surfacesensitive measurements like ARPES. To address this issue, we established three different in-situ atomic hydrogen reduction methods in an ultrahigh vacuum chamber-namely, a lab-based RF plasma cracker, an industrial RF plasma cracker, and a thermal gas cracker. Comprehensive optimization of key parameters-including hydrogen flow, RF power or filament temperature, reduction temperature, and time-was carried out for each method. Structural evolution was monitored by X-ray diffraction (XRD), surface morphology was characterized by atomic force microscopy (AFM), and superconducting properties were examined through electrical transport measurements. The results demonstrate that all three in-situ methods can achieve reduction and superconducting properties comparable to or better than CaH2 reduction. Moreover, all atomic hydrogen approaches yield lower surface roughness than CaH2 from the same precursor, highlighting their clear advantage in enhancing surface flatness. Notably, the industrial RF plasma source, owing to its higher hydrogen production efficiency, enables sufficient reduction under milder conditions, resulting in even smoother surfaces. This study also provides a detailed summary of the parameter optimization for each method, offering valuable guidance for the controlled reduction of high-quality infinite-layer nickelate thin films.
Abstract +
Graphene Dirac plasmons, which are collective oscillations of charge carriers behaving as massless Dirac fermions, have emerged as a transformative platform for nanophotonics due to their exceptional capability for deep subwavelength light confinement in the infrared to terahertz spectral regions and their unique dynamic tunability. While external controls such as electrostatic doping, mechanical strain, and substrate engineering are empirically known to modulate plasmonic responses, a comprehensive and quantitative theoretical framework from first principles is essential to decipher the distinct effciency and fundamental mechanisms of each tuning strategy. To address this, we present a systematic first-principles investigation into three primary modulation pathways-carrier density, biaxial strain, and substrate integration-using linear-response time-dependent density functional theory within the random-phase approximation (LR-TDDFT-RPA) as implemented in the computational code ABACUS. A truncated Coulomb potential was incorporated to accurately model the isolated two-dimensional system, while structural and electronic properties were computed using the PBE functional with SG15 norm-conserving pseudopoten- tials and van der Waals corrections for heterostructures. Our findings reveal that modulating carrier concentration shifts the plasmon dispersion following the characteristic ω∝ n1/4 scaling, enabling a wide tuning range from 0.45 eV to 1.38 eV at the Landau damping threshold-a 207% change for carrier densities from 0.005 to 0.1 electrons per unit cell, albeit with diminishing effciency at higher concentrations due to the sublinear nature of the scaling law. Biaxial strain linearly alters the plasmon energy by modifying the Fermi velocity (vF ) near the Dirac point, yielding a 30.4% tuning range (0.78-1.12 eV) under ±10% strain. Introducing an hBN substrate induces a small band gap (∼ 43 meV) and causes a general redshift in plasmon energy due to band renormalization, while remarkably preserving the linear straintuning capability with a 30.1% energy range (0.72-1.03 eV) in the heterostructure, demonstrating robust compatibility between strain engineering and substrate integration. These results quantitatively elucidate the distinct physical mechanisms-Fermi level shifting, Fermi velocity modification, and substrate-induced symmetry breaking and hybridization-underpinning each strategy, thereby providing a solid theoretical foundation for the design of dynamically tunable optoelectronic devices based on graphene and its van der Waals heterostructures.
Abstract +
The absolute security of quantum communication protocols relies on a critical premise: all participating parties are legitimate users. Ensuring the legitimacy of participant identities is paramount in complex real-world communication environments. Quantum Identity Authentication (QIA), leveraging fundamental principles of quantum mechanics to achieve unilateral or mutual authentication between communicating parties, constitutes an indispensable core component for building a comprehensive quantum secure communication system. It holds significant research value within the field of quantum communication.
This review employs a comparative classification approach to systematically outline the research trajectory of QIA protocols. By categorizing protocols based on the required quantum resources and the types of quantum protocols employed, it analyzes the advantages and disadvantages of various categories in terms of efficiency, security, and practicality. Single-photon protocols demand low resources, are easy to implement, and compatible with existing optical components, but require high-efficiency single-photon detectors and exhibit weak noise resistance. Entangled-state protocols offer high security and strong eavesdropping resistance, particularly suitable for long-distance or multi-party authentication. However, they heavily depend on the preparation and maintenance of high-precision, stable multi-particle entanglement sources, resulting in high experimental complexity. Continuous-variable (CV) protocols achieve high transmission efficiency in short-distance metropolitan area networks and are compatible with classical optical communication equipment, making experiments relatively straightforward. Yet, they require high-precision modulation technology and are sensitive to channel loss. Hybrid protocols aim to balance resource efficiency and security while reducing reliance on a single quantum source, but their design is complex and may introduce new attack vectors. Quantum Key Distribution (QKD) framework protocols embed identity authentication within the key distribution process, making them suitable for scenarios requiring long-term secure key distribution, though they often depend on pre-shared keys or trusted third parties. Quantum Secure Direct Communication (QSDC) framework protocols integrate authentication with secure direct information transmission, offering high efficiency for real-time communication, but demand high channel quality. Measurement-Device-Independent QSDC (MDI-QSDC) represents a crucial development direction, resisting attacks on measurement devices. Quantum Teleportation (QT) framework protocols enable cross-node authentication and unconditional security, applicable to quantum relay networks, albeit with high experimental complexity. Entanglement swapping framework protocols can resist conspiracy attacks and are suitable for multi-party joint scenarios, but consume significant resources and rely on trusted third parties. Ping-pong protocol framework supports dynamic key updates and exhibits strong eavesdropping resistance, fitting for temporary authentication on mobile terminals, though it typically supports only unilateral authentication and requires a bidirectional channel.
Subsequently, this review details our research group's latest QIA protocols, including a multi-party synchronous identity authentication protocol based on Greenberger-Horne-Zeilinger (GHZ) states, and a tripartite QSDC protocol with identity authentication capabilities utilizing polarization-spatial super-coding. The GHZ-based multi-party synchronous authentication protocol leverages the strong correlations inherent in GHZ states to achieve simultaneous authentication among multiple parties. Through a carefully designed two-round decoy-state detection mechanism, it effectively resists both external eavesdropping and internal attacks originating from authenticated users, thereby enhancing the efficiency and security of identity management in large-scale quantum networks. The core innovation of the polarization-spatial super-coding tripartite QSDC protocol lies in its deep integration of the authentication process with information transmission utilizing the spatial degrees of freedom of single photons. This design accomplishes the identity verification of two senders and the transmission of secret information within a single protocol run, ensuring end-to-end security through a three-stage security check. This "authentication-as-communication" paradigm significantly improves the overall efficiency and practicality of the protocol. Its successful implementation also relies on advancements in quantum memory technology.
Finally, the review provides an outlook on future research directions for quantum identity authentication and its application potential within quantum communication. QIA research needs to focus on reducing resource dependency, exploring more efficient protocol designs, further enhancing protocol integration and robustness, prioritizing the development of protocols adaptable to real-world environments, and actively investigating integration with novel scenarios. This comprehensive review aims to provide theoretical research foundations and technical support for the practical development of future quantum identity authentication.
This review employs a comparative classification approach to systematically outline the research trajectory of QIA protocols. By categorizing protocols based on the required quantum resources and the types of quantum protocols employed, it analyzes the advantages and disadvantages of various categories in terms of efficiency, security, and practicality. Single-photon protocols demand low resources, are easy to implement, and compatible with existing optical components, but require high-efficiency single-photon detectors and exhibit weak noise resistance. Entangled-state protocols offer high security and strong eavesdropping resistance, particularly suitable for long-distance or multi-party authentication. However, they heavily depend on the preparation and maintenance of high-precision, stable multi-particle entanglement sources, resulting in high experimental complexity. Continuous-variable (CV) protocols achieve high transmission efficiency in short-distance metropolitan area networks and are compatible with classical optical communication equipment, making experiments relatively straightforward. Yet, they require high-precision modulation technology and are sensitive to channel loss. Hybrid protocols aim to balance resource efficiency and security while reducing reliance on a single quantum source, but their design is complex and may introduce new attack vectors. Quantum Key Distribution (QKD) framework protocols embed identity authentication within the key distribution process, making them suitable for scenarios requiring long-term secure key distribution, though they often depend on pre-shared keys or trusted third parties. Quantum Secure Direct Communication (QSDC) framework protocols integrate authentication with secure direct information transmission, offering high efficiency for real-time communication, but demand high channel quality. Measurement-Device-Independent QSDC (MDI-QSDC) represents a crucial development direction, resisting attacks on measurement devices. Quantum Teleportation (QT) framework protocols enable cross-node authentication and unconditional security, applicable to quantum relay networks, albeit with high experimental complexity. Entanglement swapping framework protocols can resist conspiracy attacks and are suitable for multi-party joint scenarios, but consume significant resources and rely on trusted third parties. Ping-pong protocol framework supports dynamic key updates and exhibits strong eavesdropping resistance, fitting for temporary authentication on mobile terminals, though it typically supports only unilateral authentication and requires a bidirectional channel.
Subsequently, this review details our research group's latest QIA protocols, including a multi-party synchronous identity authentication protocol based on Greenberger-Horne-Zeilinger (GHZ) states, and a tripartite QSDC protocol with identity authentication capabilities utilizing polarization-spatial super-coding. The GHZ-based multi-party synchronous authentication protocol leverages the strong correlations inherent in GHZ states to achieve simultaneous authentication among multiple parties. Through a carefully designed two-round decoy-state detection mechanism, it effectively resists both external eavesdropping and internal attacks originating from authenticated users, thereby enhancing the efficiency and security of identity management in large-scale quantum networks. The core innovation of the polarization-spatial super-coding tripartite QSDC protocol lies in its deep integration of the authentication process with information transmission utilizing the spatial degrees of freedom of single photons. This design accomplishes the identity verification of two senders and the transmission of secret information within a single protocol run, ensuring end-to-end security through a three-stage security check. This "authentication-as-communication" paradigm significantly improves the overall efficiency and practicality of the protocol. Its successful implementation also relies on advancements in quantum memory technology.
Finally, the review provides an outlook on future research directions for quantum identity authentication and its application potential within quantum communication. QIA research needs to focus on reducing resource dependency, exploring more efficient protocol designs, further enhancing protocol integration and robustness, prioritizing the development of protocols adaptable to real-world environments, and actively investigating integration with novel scenarios. This comprehensive review aims to provide theoretical research foundations and technical support for the practical development of future quantum identity authentication.
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Abstract +
Liquid evaporation at the nanoscale is significantly enhanced by microscopic effects, with its rate even exceeding the predicted upper limit of the classical HertzKnudsen equation. This property makes nanoscale liquid evaporation highly valuable for applications in solar-driven interfacial evaporation, electronics cooling, and microfluidics. However, existing research predominantly focuses on the influence of individual microscopic effects, leaving the synergistic mechanisms of multiple effects poorly understood. To deeply reveal the microscopic mechanism of liquid phase change at the nanoscale, this study employs liquid argon as a model system to systematically investigate the synergistic effect of potential energy and cavitation on its evaporation. Using molecular dynamics simulations, we studied the evaporation process of liquid argon within nanochannels characterized by different solid-liquid interaction strengths under identical temperature and time frames. The results indicate that an increase in the solid-liquid interaction strength reduces the average potential energy of liquid argon and increases the evaporation energy barrier, which theoretically should suppress evaporation. Nevertheless, the capillary pressure induced by the increased meniscus curvature leads to negative pressure within the liquid argon, triggering a cavitation effect. This cavitation generates bubbles inside the liquid argon, which significantly increases the evaporation surface area and consequently promotes evaporation. Furthermore, the meniscus-dominated evaporation mode is gradually weakened, while the contribution from cavitation bubbles becomes increasingly pronounced. This study demonstrates that the evaporation rates of liquid argon in the four nanochannels with different interaction strengths are 3.49×10-14 kg/s, 3.95×10-14 kg/s, 3.02×10-14 kg/s, and 2.44×10-14 kg/s, respectively. Therefore, it is concluded that the evaporation rate does not vary linearly with increasing solid-liquid interaction strength. Instead, the synergistic state between potential energy and the cavitation effect is optimized at a medium interaction strength, leading to a maximum evaporation rate.
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Abstract +
Magnesium and aluminum are abundant metals in the Earth's crust and are widely utilized in industrial engineering. Under high pressure, these elements can form elemental compounds as single substances, leading to a variety of crystal structures and electronic properties. This study systematically investigated the possible structures of magnesium-aluminum alloys within the pressure range of 0-500 GPa using the first-principles structure search method, with energy and electronic structure calculations conducted using the VASP package. Bader charge analysis characterized atomic and interstitial quasiatom (ISQ) valence states, while lattice dynamics were analyzed using the PHONOPY package via the small-displacement supercell approach. Eight stable phases (MgAl3-Pm-3m、 MgAl3-P63/mmc、 MgAl-P4/mmm、 MgAl-Pmmb、 MgAl-Fd-3m、 Mg2Al-P-3m1、 Mg3Al-P63/mmc、 Mg3Al-Fm-3m) and two metastable phases (Mg4Al-I4/m、 Mg5Al-P-3m1) were identified. The critical pressures and stable intervals for phase transitions were precisely determined. Notably, MgAl-Fd-3m、 Mg2Al-P-3m1、 Mg4Al-I4/m and Mg5Al-P-3m1 represent newly predicted structures. Analysis of electronic localization characteristics revealed that six stable structures (MgAl3-Pm-3m 、 MgAl3-P63/mmc 、 MgAl-Pmmb 、 MgAl-Fd-3m 、 Mg2Al-P-3m1 and Mg3Al-P63/mmc) exhibit electronic properties of electrides. Interstitial quasi-atoms (ISQs) primarily originate from charge transfer of Mg atoms. In the metastable phase Mg4Al-I4/m, it was predicted that Al atoms achieve an Al5- valence state, filling the p shell. This finding demonstrates that by adjusting the Mg/Al ratio and pressure conditions, a transition from traditional electrides to high negative valence states can be realized, offering new insights into the development of novel high-pressure functional materials. Furthermore, all Mg-Al compounds display metallic behavior, with their stability attributed to Al-p-d orbital hybridization, which significantly contributes to the Al-3p/3d orbitals near the Fermi level. Additionally, LA-TA splitting was observed in MgAl3-Pm-3m, with a splitting value of 45.49 cm-1, confirming the unique regulatory effect of ISQs on lattice vibrational properties. These results elucidate the rich structural and electronic properties of magnesium-aluminum alloys as electrides, providing deeper insights into their behavior under high pressure and inspiring further exploration of structural and property changes in high-pressure alloys composed of light metal elements and p-electron metals.
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Abstract +
In quantum resource theories, manipulating and transformation resource states are often challenging due to the presence of noise. Resource manipulation procedures, from high resource states ρ to low resource states ρ', involving asymptotically many copies of states can be considered to overcome the problem. Here, the asymptomatic transformation rate R(ρ→ρ') can characterize the corresponding quantum manipulation power, and can be calculated as the ratio of the copy number of initial states to the copy number of target states. Generally, exact computations of asymptotic transformation rates are challenging, so it is important to establish rigorous and computable bounds on them. Recently, Ganardi et al. show that the transformation rate to any pure state is superadditive for the distillable entanglement. However, it has remained a question whether the transformation rate to any noise state is also superadditive in the general resource theory. Firstly, we study the general superadditive inequalities satisfied by the transformation rate R(ρ→ρ') to any noise stateρ'. In any multiple quantum resource theory, we also show that the bipartite asymptomatic transformation rate obey some distributed relations: when α ≥1,Rα(ρ→ρ') satisfies monogamy relations. Using similar methods, we demonstrate that marginal asymptotic transformation rates and marginal catalytic transformation rates are all satisfies these relations. As a byproduct, we show an equivalence among the asymptomatic transformation rate, marginal asymptotic transformations and marginal catalytic transformations under some restrictions. Here marginal asymptotic transformations and marginal catalytic transformations are special asymptotic transformations, and initial states can be reducible onto target states at nonzero rates. These inequality relations give rise to a new kind of restrictions on the quantum resource distribution and trade off among subsystems. Recently, reversible quantum resource manipulations have been researched, where they have been conjectured that transformations could be executed reversibly in an asymptotic regime. In the future, we will explore a conclusive proof of this conjecture and then study distributions of these reversible manipulations.
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Abstract +
Very-low-frequency (VLF) acoustic waves (≤100 Hz) exhibit special propagation characteristics in the deep sea, owing to strong penetration capability and interaction with deep geological structures. During a deep sea experiment conducted in the South China Sea, a vertical linear array including 64 elements was moored to the bottom (approximately 4360 m depth) to receive the acoustic signal. In the bearing-time record proceed by beamforming,a high-energy bottom bounce path is observed from the ship noise received by the bottom-moored vertical linear array. This shows an abrupt increasing in energy near a 45° grazing angle. However, the physical mechanism causing this phenomenon remains unclear, and we investigate it further in this paper. Based on the data processing, we developed an environmental model of the seabed that incorporates continuous speed gradient, which arises from long-term geological compaction processes, in the sediment. This model is contrasted with a traditional stratified model assuming a uniform sediment layer. The wavenumber integration method is adopted for numerical simulation to accurately calculate the pressure field and analyze the cross-media propagation. The numerical simulations demonstrated that the positive velocity gradient (increasing from 1600 m/s to 2144 m/s) causes an ‘acoustic turning’ effect, which reradiates substantial acoustic energy back into the water column and generates observed high-energy bounce paths. This is supported by theoretical analysis using the WKB approximation, where the calculated reflection coefficient shows a sharp transition in the acoustic turning point, accounting for the energy fluctuations observed in the experimental bearing-time record (BTR). Further analysis shows that the thickness of sediment influences the angular separation between bottom bounce paths, while its sound speed structure dictates the turning angle. These findings provide new insights into VLF acoustic propagation in the deep sea and offer critical evidence supporting a transition from simplified stratified models towards a more realistic model with a continuous gradient structure. Furthermore, the discovery of high-energy bottom bounce paths provides a new way to enhance capabilities of underwater detection, and these observed characteristics also offer reliable pressure field features for the inversion of deep seabed parameters.
, , Received Date: 2025-05-27
Abstract +
Plasmonic solar water splitting is produced on the composite electrode with plasmonic metal nanoparticles loaded on semiconductor, where the localized heating generated by relaxation of the metal’s localized surface plasmon resonance (LSPR) under light excitation enhances hydrogen production efficiency. To optimize composite photoanodes for photoelectrochemical water splitting system, the non-equilibrium molecular dynamics simulations are conducted to obtain the interfacial thermal conductivity between plasmonic metals (Cu, Ag, Au) and semiconductors (TiO2, ZnO, MoS2) at varying temperatures. The relationship between interfacial thermal conductivity and phonons at different frequencies is investigated via vibrational density of states which is calculated from the velocity autocorrelation functions and subsequent phonon participation ratio. The results indicate that as he temperature increases, the interfacial thermal conductivity of all composite electrode configurations is enhanced. When Cu and Ag are combined with TiO2 into Cu-TiO2 and Ag-TiO2, respectively, the thermal transport performances of Cu-TiO2 and Ag-TiO2 are superior to Au-TiO2, and the interfacial thermal conductivity of Cu-TiO2 reaches 973.56 MW·m–2·K–1 at 800 K. With Au as the fixed plasmonic component, Au-ZnO shows that its interfacial thermal conductivity reaches 324.44 MW·m–2·K–1 at 800 K, which is higher than those of Au-MoS2 and Au-TiO2. Based on the obtained interfacial thermal conductivity of different composite photoanodes, it is predicted that Cu-ZnO is the optimal composite, but its interfacial thermal conductivity is 547.69 MW·m–2·K–1 at 800 K, second only to Cu-TiO2. The analysis of vibrational density of states and phonon participation ratio shows that the low-frequency region (0—10 THz) is the main region for thermal transport, and both interfaces exhibit a high phonon participation ratio range of 0.7—0.8. However, the Cu-TiO2 possesses much higher vibrational density of states than Cu-ZnO within this critical band. Although Cu-ZnO exhibits a higher phonon participation ratio range in the high-frequency range, its lower overall interfacial thermal conductivity is attributed to the minimal contribution of high-frequency phonons to interfacial thermal conductance. The findings provide optimization strategies based on interfacial thermal transport mechanisms for constructing efficient photoanodes for solar water splitting.
, , Received Date: 2025-05-16
Abstract +
Realizing the independent control of the national standard time has important practical significance under the current international situation. In this work, an independent time scale that does not rely on external references is developed by studying the self-developed cesium fountain primary frequency standard and domestically-produced optically-pumped small cesium clocks. The specific approach is to use the cesium fountain primary frequency standard as a frequency reference to predict the frequency drift of the optically pumped small cesium clocks. By analyzing the noise characteristics of the optically pumped small cesium clocks, the state equation of the atomic clock is established, and the state of the optically pumped small cesium clock is estimated based on the Kalman filtering algorithm. The calculation of the time scale is based on the frequency state estimation and frequency drift state estimation of atomic clocks, which serve as the forecast values, and is achieved through the weight algorithm. The weight algorithm based on prediction error and the weight algorithm based on noise characteristics are studied. The results show that in the case of using Kalman filtering state estimation, the weight algorithm based on prediction error significantly improves the accuracy of the independent time scale. The cesium fountain primary frequency standard is chosen as the frequency reference to predict the frequency drift of the optically pumped small cesium clock. The accuracy and long-term stability of the independent time scale calculated are much better than those when the time scale itself is used as the frequency reference. Taking the international standard time (UTCr) as the reference, the accuracy of the independent time scale is maintained within 15 ns. The frequency stability is 1.57 × 10–14 for a sampling interval of 1 day, 4.29 × 10–15 for a sampling interval of 15 days, and 2.87 × 10–15 for a sampling interval of 30 days is showing that its stability can meet the current national time demand.
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