Universal cooling dynamics toward a quantum critical point

TL;DR

This paper explores how quantum systems lose adiabaticity when cooled toward a quantum critical point, revealing universal scaling laws that connect cooling dynamics with critical exponents, enabling finite-temperature quantum criticality probing.

Contribution

It demonstrates universal scaling laws for excitation density during cooling near quantum critical points, valid for general conditions and analytically shown for a Kitaev wire.

Findings

Scaling laws govern excitation density in cooling protocols.

Quantum critical properties can be probed dynamically at finite temperatures.

Analytical validation for a Kitaev quantum wire model.

Abstract

We investigate the loss of adiabaticity when cooling a many-body quantum system from an initial thermal state toward a quantum critical point. The excitation density, which quantifies the degree of adiabaticity of the dynamics, is found to obey scaling laws in the cooling velocity as well as in the initial and final temperatures of the cooling protocol. The scaling laws are universal, governed by the critical exponents of the quantum phase transition. The validity of these statements is shown analytically for a Kitaev quantum wire coupled to Markovian baths and argued to be valid under rather general conditions. Our results establish that quantum critical properties can be probed dynamically at finite temperature, without even varying the control parameter of the quantum phase transition.