Quantum Refrigerators and the Iii-law of Thermodynamics

Quantum thermodynamics addresses the emergence of thermodynamical laws from quantum mechanics. The III-law of thermodynamics has been mostly ignored. There are seemingly two independent formulation of the third law of thermodynamics, both originally stated by Nernst. The first is known as Nernst heat theorem, which is purely static, and implies that the entropy flow from any substance at the absolute zero is zero. And the second formulation known as the unattainability principle practically state that no refrigerator can cool a system to absolute zero at finite time. We explore the dynamic version which is the vanishing of rate of temperature decrease of a cooled quantum bath when T → 0. The III-law is then quantified dynamically by evaluating the characteristic exponent ξ of the cooling process: dT (t)