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研究了格点势能Vn=λtanh［Acos(2πσn)］/tanhA，σ=(5-1)/2的一类非公度体系的电子动力学性质-分析了体系中不同相区内波函数的特征，发现延展态的波函数类似于Bloch波，在一定范围内体系中存在临界态-计算了自关联函数C(t)和均方位移d(t)，分析了它们的长时行为，发现当体系各态均为延展态时，C(t)～t-1,d(t)～t1；当体系各态均为局域态时，C(t)～t0,d(t)～t0The electronic dynamics of an incommensurate system have been studied with site potentials Vn=λtanh［Acos(2πσn)］/tahnA, where σ=(5-1)/2. By analyzing the wave function, we find the extended eigenstates are similar to the Bloch waves, and critical states occur in some Hamiltonian parameter regions. Much attention is paid to the long-time behavior of the autocorrelation function C(t) and mean square displacement d(t). When all states in the system become extended, C(t)～t-1 and d(t)～t1. In the regime with absolute localized states, C(t)～t0 and d(t)～t0. Between these two extremes, there exists a complex phase regime in which extended states, critical states and localized states coexist, and the behavior of C(t) is related to the initial site, but with d(t)～t1. Moreover, the relation between C(t) and the local spectral probability R(l) have been studied.
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物理学报. 1999, 48(3): 497-504.
doi: 10.7498/aps.48.497.
一类非公度体系的电子动力学
- 收稿日期: 1998-07-14
- 刊出日期: 1999-03-20
摘要: 研究了格点势能Vn=λtanh［Acos(2πσn)］/tanhA，σ=(5-1)/2的一类非公度体系的电子动力学性质-分析了体系中不同相区内波函数的特征，发现延展态的波函数类似于Bloch波，在一定范围内体系中存在临界态-计算了自关联函数C(t)和均方位移d(t)，分析了它们的长时行为，发现当体系各态均为延展态时，C(t)～t-1,d(t)～t1；当体系各态均为局域态时，C(t)～t0,d(t)～t0
English Abstract
ELECTRONIC DYNAMICS IN AN INCOMMENSURATE SYSTEM
- Received Date:
14 July 1998
- Published Online:
20 March 1999
Abstract: The electronic dynamics of an incommensurate system have been studied with site potentials Vn=λtanh［Acos(2πσn)］/tahnA, where σ=(5-1)/2. By analyzing the wave function, we find the extended eigenstates are similar to the Bloch waves, and critical states occur in some Hamiltonian parameter regions. Much attention is paid to the long-time behavior of the autocorrelation function C(t) and mean square displacement d(t). When all states in the system become extended, C(t)～t-1 and d(t)～t1. In the regime with absolute localized states, C(t)～t0 and d(t)～t0. Between these two extremes, there exists a complex phase regime in which extended states, critical states and localized states coexist, and the behavior of C(t) is related to the initial site, but with d(t)～t1. Moreover, the relation between C(t) and the local spectral probability R(l) have been studied.
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