Quantum adiabatic cycles and their breakdown

TL;DR

This paper introduces an analytically solvable model demonstrating that adiabaticity breakdown is a universal feature in quantum systems near critical points, revealing an 'anti-adiabatic' phase and implications for defect formation.

Contribution

The study provides a new solvable model showing adiabaticity breakdown and the existence of an anti-adiabatic phase in quantum critical dynamics.

Findings

Adiabaticity breaks down universally near quantum critical points.

Existence of an anti-adiabatic dynamical phase with zero ground state fidelity.

Connections to the Kibble-Zurek mechanism and defect formation.

Abstract

An analytically solvable model for quasi-static transformations across quantum critical points featuring Bosonic quasi-particle excitations is presented. The model proves that adiabaticity breakdown is a general feature of universal slow dynamics in these systems. The existence of an "anti-adiabatic" dynamical phase with vanishing ground state fidelity in the slow drive limit is also proven. The relation of these findings with the Kibble-Zurek mechanism and their consequences on defect formation in many body systems ramped across a quantum phase transition are discussed.