Chinese Physics C
HIGH-ORDER ADIABATIC APPROXIMATIONS FOR EVOLUTION OF DEGENERATE QUANTUM MECHANICAL SYSTEM AND NON-ABELIAN INDUCED GAUGE STRUCTURE
Chen Sun
Abstract
In this paper high-order adiabatic approximate method is proposed to study the evolution of degenerate quantum systums with slowly-changing parameters and varying symmetry. We not only prove the quantum adiabatic theorem for degenerate cases and discuss the corresponding non-abelian induced gauge structure, but also point out the non-adiabatic corrections resulting from higher-order approximations. With nuclear quadrupole resonance as an explicit example, we use this method to analyse observable effects of non-abelian Berry's phases in adiabatic and non-adiabatic experimental process.