Tunable Aharonov-Bohm-like cages for quantum walks

Article

关键词: WAVE-FUNCTIONS;    LOCALIZATION;    SPACE;   

DOI  :  10.1103/PhysRevB.101.235167

来源: SCIE

【 摘 要 】

Aharonov-Bohm cages correspond to an extreme confinement for two-dimensional tight-binding electrons in a transverse magnetic field. When the dimensionless magnetic flux per plaquette f equals a critical value f(c) = 1/2, a destructive interference forbids the particle to diffuse away from a small cluster. The corresponding energy levels pinch into a set of highly degenerate discrete levels as f -> f(c). We show here that cages also occur for discrete-time quantum walks on either the diamond chain or the T-3 tiling but require specific coin operators. The corresponding quasienergies versus f result in a Floquet-Hofstadter butterfly displaying pinching near a critical flux f(c) and that may be tuned away from 1/2. The spatial extension of the associated cages can also be engineered.

【 授权许可】

Free