Nonadiabatic noncyclic geometric phase and persistent current in one-dimensional rings

Persistent current and Drude weight in one-dimensional rings with substitution potentials

Persistent currents and Drude weights are investigated for the tight-binding approximation to one-dimensional rings threaded by a magnetic flux and with potential given by some almost-periodic substitution sequences with different degrees of randomness, and for various potential strengths. The Drude weight D distinguishes correctly conductors and insulators, in accordance with the results shown...

Nonadiabatic Geometric Phase in Quaternionic Hilbert Space

We develop the theory of the nonadiabatic geometric phase, in both the Abelian and non-Abelian cases, in quaternionic Hilbert space.

Persistent current of one-dimensional perfect rings under the canonical ensemble.

Noncyclic Geometric Phase and Its Non-Abelian Generalization

We use the theory of dynamical invariants to yield a simple derivation of noncyclic analogues of the Abelian and non-Abelian geometric phases. This derivation relies only on the principle of gauge invariance and elucidates the existing definitions of the Abelian noncyclic geometric phase. We also discuss the adiabatic limit of the noncyclic geometric phase and compute the adiabatic non-Abelian ...

Nonadiabatic conditional geometric phase shift with NMR.

A conditional geometric phase shift gate, which is fault tolerant to certain types of errors due to its geometric nature, was realized recently via nuclear magnetic resonance (NMR) under adiabatic conditions. However, in quantum computation, everything must be completed within the decoherence time. The adiabatic condition makes any fast conditional Berry phase (cyclic adiabatic geometric phase)...