2007/08/31 by Hendrik Weimer, H. Weimer, M. J. Henrich +7 · 2 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Quantum many-body systems #Statistical Mechanics and Entropy #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1209/0295-5075/83/30008
published as Europhys. Lett. 83, 30008 (2008) · 5 pages, 1 figure, published version
openalex publication_date 2008/07/18 · arxiv created 2008/08/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
By computing the local energy expectation values with respect to some local measurement basis we show that for any quantum system there are two fundamentally different contributions: changes in energy that do not alter the local von Neumann entropy and changes that do. We identify the former as work and the latter as heat. Since our derivation makes no assumptions on the system Hamiltonian or its state, the result is valid even for states arbitrarily far from equilibrium. Examples are discussed ranging from the classical limit to purely quantum-mechanical scenarios, i.e. where the Hamiltonian and the density operator do not commute.