2008/04/01 by Noam Erez, Goren Gordon, Mathias Nest +1 · 1 citation
Computer Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1038/nature06873
published as Nature 452, 724 (2008) · 10 Pages. Pre-submission version of Nature {\bf 452}, 724 (2008). Includes Supplementary Information
openalex publication_date 2008/04/01 · arxiv created 2008/04/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Heat flow between a large ``bath'' and a smaller system brings them progressively closer to thermal equilibrium while increasing their entropy. Deviations from this trend are fluctuations involving a small fraction of a statistical ensemble of systems interacting with the bath: in this respect, quantum and classical thermodynamics are in agreement. Can there be drastic differences between them? Here we address a distinctly quantum mechanical setting that displays such differences: disturbances of thermal equilibrium between two-level systems (TLS) and a bath by frequent and brief quantum (non-demolishing) measurements of the TLS energy-states. If the measurements are frequent enough to induce either the Zeno or the anti-Zeno regime, namely, the slowdown or speedup of the TLS relaxation, then the resulting entropy and temperature of both the system and the bath are found to be completely unrelated to what is expected by standard thermodynamical rules that hold for memoryless baths. The practical advantage of these anomalies is the possibility of very fast control of heat and entropy, allowing cooling and state-purification of quantum systems much sooner than their thermal equilibration time.