Quantum mechanical position operator and localization in extended systems

被引：77

作者：

Aligia, AA ^{[1
]}

Ortiz, G

机构：

[1] Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina

[2] Inst Balseiro, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina

[3] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA

来源：

PHYSICAL REVIEW LETTERS | 1999年 / 82卷 / 12期

关键词：

D O I：

10.1103/PhysRevLett.82.2560

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We introduce a fundamental complex quantity, Z(L), which allows us to discriminate between conducting and nonconducting thermodynamic phases in extended quantum systems. Its phase can be related to the expectation value of the position operator, while its modulus provides an appropriate definition of a localization length. The expressions are valid for any fractional particle filling. As an illustration we use z(L) to characterize insulator to "superconducting" and Mott transitions in one-dimensional lattice models with infinite on-site Coulomb repulsion at quarter filling. [S0031-9007(99)08740-2].

引用

页码：2560 / 2563

页数：4

共 13 条

[1] Superconductor-insulator transitions in a Hubbard chain with nearest-neighbor and bond-charge interactions [J].