On the correspondence between classical geometric phase of gyro-motion and quantum Berry phase

TL;DR

This paper demonstrates that the classical geometric phase of a charged particle's gyro-motion in a magnetic field can be derived from a quantum Berry phase of coherent states, establishing a direct classical-quantum correspondence.

Contribution

The authors construct coherent states from Landau level eigenstates to connect classical gyro-phase with quantum Berry phase, including spin effects.

Findings

Coherent states maintain their form during slow magnetic field variation.

Orbital Berry phases interfere to produce a classical-like geometric phase.

Spin Berry phases do not contribute to the classical geometric phase.

Abstract

We show that the geometric phase of the gyro-motion of a classical charged particle in a uniform time-dependent magnetic field described by Newton's equation can be derived from a coherent Berry phase for the coherent states of the Schroedinger equation or the Dirac equation. This correspondence is established by constructing coherent states for a particle using the energy eigenstates on the Landau levels and proving that the coherent states can maintain their status of coherent states during the slow varying of the magnetic field. It is discovered that orbital Berry phases of the eigenstates interfere coherently to produce an observable effect (which we termed "coherent Berry phase"), which is exactly the geometric phase of the classical gyro-motion. This technique works for particles with and without spin. For particles with spin, on each of the eigenstates that makes up the coherent states, the Berry phase consists of two parts that can be identified as those due to the orbital and the spin motion. It is the orbital Berry phases that interfere coherently to produce a coherent Berry phase corresponding to the classical geometric phase of the gyro-motion. The spin Berry phases of the eigenstates, on the other hand, remain to be quantum phase factors for the coherent states and have no classical counterpart.