Zhao Shi-Ping^{1}, Liu Yu-Xi^{2}, Zheng Dong-Ning^{1,3}

1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; 2. Institute of Microelectronics, Tsinghua University, Tsinghua National Laboratory for Information Science and Technology, Beijing 100084, China; 3. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China

Abstract In the past years, superconducting quantum computation has received much attention and significant progress of the device design and fabrication has been made, which leads qubit coherence times to be improved greatly. Recently, we have successfully designed, fabricated, and tested the superconducting qubits based on the negative-inductance superconducting quantum interference devices (nSQUIDs), which are expected to have the advantages for the fast quantum information transfer and macroscopic quantum phenomenon study with a two-dimensional potential landscape. Their quantum coherence and basic physical properties have been demonstrated and systematically investigated. On the other hand, a new type of superconducting qubit, called transmon and Xmon qubit, has been developed in the meantime by the international community, whose coherence time has been gradually increased to the present scale of tens of microseconds. These devices are demonstrated to have many advantages in the sample design and fabrication, and multi-qubit coupling and manipulation. We have also studied this type of superconducting qubit. In collaboration with Zhejiang University and the University of Science and Technology of China, we have successfully fabricated various types of the coupled Xmon devices having the qubit numbers ranging from 4 to 10. Quantum entanglement, quantum algorithm of solving coupled linear equations, and quantum simulation of the many-body localization problem in solid-state physics have been demonstrated by using these devices. Also, we have made significant achievements in the studies of the macroscopic quantum phenomena, quantum dissipation, quantum microwave lasing, and some other quantum optics problems. In particular, Autler-Townes splitting under strong microwave drive, electromagnetically induced transparency, stimulated Raman adiabatic passage, microwave mixing, correlated emission lasing, and microwave frequency up-and-down conversion have been successfully studied, both experimentally and theoretically.

Makhlin Y, Schon G, Shnirman A 2001 Rev. Mod. Phys. 73 357

[2]

Wendin G, Shumeiko V S 2006 in Rieth M, Schommers W eds. Handbook of Theoretical and Computational Nanotechnology (American Scientific Publishers)

[3]

Clarke J, Wilhelm F K 2008 Nature 453 1031

[4]

Devoret M H, Schoelkopf R J 2013 Science 339 1169

[5]

Wendin G 2016 arXiv: 161002208 [quant-ph] [2018-4-28]

[6]

Liu W Y, Zheng D N, Zhao S P 2018 Chin. Phys. B 27 027401

[7]

Gu X, Kockum A F, Miranowicz A, Liu Y X, Nori F 2017 Phys. Rep. 718-719 1

[8]

Su F F, Liu W Y, Xu H K, Deng H, Li Z Y, Tian Ye, Zhu X B, Zheng D N, Lu Li, Zhao S P 2017 Chin. Phys. B 26 060308

[9]

Xue G M, Deng H, Tian Ye, Liu W Y, Xu H K, Zheng D N, Zhao S P Chinese Patent Z L 2017 201410475485X (in Chinese) [薛光明, 邓辉, 田野, 刘伟洋, 徐晖凯, 郑东宁, 赵士平 2017 中国专利 ZL 201410475485X]

[10]

Liu W Y, Su F F, Xu H K, Li Z Y, Tian Ye, Zhu X B, Lu Li, Han S, Zhao S P 2018 Supercond. Sci. Technol. 31 045003

[11]

Jin Y R, Deng H, Guo X Y, Zheng Y R, Huang K Q, Ning L H, Zheng D N 2017 IEEE Trans. Appl. Supercond. 27 1501904

[12]

Liu W Y, Xu H K, Su F F, Li Z Y, Tian Ye, Han S, Zhao S P 2018 Phys. Rev. B 97 094513

[13]

Huang K Q, Guo Q J, Song C, Zheng Y R, Deng H, Wu Y L, Jin Y R, Zhu X B, Zheng D N 2017 Chin. Phys. B 26 094203

[14]

Zheng Y R, Song C, Chen M C, Xia B X, Liu W X, Guo Q J, Zhang L B, Xu D, Deng H, Huang K Q, Wu Y L, Yan Z G, Zheng D N, Lu Li, Pan J W, Wang H, Lu C Y, Zhu X B 2017 Phys. Rev. Lett. 118 210504

[15]

Song C, Xu K, Liu W X, Yang C P, Zheng S B, Deng H, Xie Q W, Huang K Q, Guo Q J, Zhang L B, Zhang P F, Xu D, Zheng D N, Zhu X B, Wang H, Chen Y A, Lu C Y, Han S, Pan J W 2017 Phys. Rev. Lett. 119 180511

[16]

Xu K, Chen J J, Zeng Y, Zhang Y R, Song C, Liu W X, Guo Q J, Zhang P F, Xu D, Deng H, Huang K Q, Wang H, Zhu X B, Zheng D N, Fan H 2018 Phys. Rev. Lett. 120 050507

[17]

Xue G M, Gong M, Xu H K, Liu W Y, Deng H, Tian Ye, Yu H F, Yu Y, Zheng D N, Zhao S P, Han S 2014 Phys. Rev. B 90 224505

[18]

Sun H C, Liu Y X, Ian H, You J Q, Il’ichev E, Nori F 2014 Phys. Rev. A 89 063822

[19]

Gu X, Huai S N, Nori F, Liu Y X 2016 Phys. Rev. A 93 063827

[20]

Long J L, Ku H S, Wu X, Gu X, Lake R E, Bal M, Liu Y X, Pappas D P 2018 Phys. Rev. Lett. 120 083602

[21]

Ding J H, Huai S N, Ian H, Liu Y X 2018 Sci. Rep. 8 4507

[22]

Peng Z H, Ding J H, Zhou Y, Ying L L, Wang Z, Zhou L, Kuang L M, Liu Y X, Astfiev O, Tsai J S 2017 arXiv:170511118 [quant-ph] [2018-4-28]

[23]

Liu Y X, Xu X W, Miranowicz A, Nori F 2014 Phys. Rev. A 89 043818

[24]

Xu H K, Song C, Liu W Y, Xue G M, Su F F, Deng H, Tian Ye, Zheng D N, Han S, Zhong Y P, Wang H, Liu Y X, Zhao S P 2016 Nat. Commun. 7 11018

[25]

Wu Y L, Yang L P, Zheng Y R, Deng H, Yan Z G, Zhao Y J, Huang K Q, Munro W J, Nemoto K, Zheng D N, Sun C P, Liu Y X, Zhu X B, Lu Li 2018 npj Quantum Information 4 50

[26]

Zhao Y J, Liu Y L, Liu Y X, Nori F 2015 Phys. Rev. A 91 053820

[27]

Zhao Y J, Wang C Q, Zhu X B, Liu Y X 2016 Sci. Rep. 6 23646

[28]

Peng Z H, Liu Y X, Peltonen J T, Yamamoto T, Tsai J S, Astafiev O 2015 Phys. Rev. Lett. 115 223603

[29]

Liu Y X, Sun H C, Peng Z H, Miranowicz A, Tsai J S, Nori F 2014 Sci. Rep. 4 7289

[30]

Jia W Z, Wang Y W, Liu Y X 2017 Phys. Rev. A 96 053832

[31]

Zhao Y J, Ding J H, Peng Z H, Liu Y X 2017 Phys. Rev. A 95 043806

[32]

Tanamoto T, Ono K, Liu Y X, Nori F 2015 Sci. Rep. 5 10076

[33]

Gu X, Chen S, Liu Y X 2017 arXiv:171106829 [quant-ph] [2018-4-28]