Abstract
A minimal model of a quantum refrigerator, i.e., a periodically phase-flipped two-level system permanently coupled to a finite-capacity bath (cold bath) and an infinite heat dump (hot bath), is introduced and used to investigate the cooling of the cold bath towards absolute zero (). Remarkably, the temperature scaling of the cold-bath cooling rate reveals that it does not vanish as for certain realistic quantized baths, e.g., phonons in strongly disordered media (fractons) or quantized spin waves in ferromagnets (magnons). This result challenges Nernst’s third-law formulation known as the unattainability principle.
- Received 21 May 2012
DOI:https://doi.org/10.1103/PhysRevLett.109.090601
© 2012 American Physical Society