Universal Cooling Dynamics toward a Quantum Critical Point

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.

Automated summary

We studied the Adiabatic loss in cooling a many-body quantum system towards a quantum critical point. The excitation density that represents the degree of adiabaticity follows scaling laws with cooling velocity, initial, and final temperatures. These scaling laws are universal and depend on the critical exponents of the quantum phase transition. We analytically showed the validity of these statements for a Kitaev quantum wire coupled to Markovian baths and argued their general applicability.