Deffner, SebastianZurek, Wojciech H2020-08-132020-08-132016-06-09Sebastian Deffner and Wojciech H Zurek, Foundations of statistical mechanics from symmetries of entanglement, New Journal of Physics, Volume 18 (2016), 10.1088/1367-2630/18/6/06301310.1088/1367-2630/18/6/063013http://hdl.handle.net/11603/19422Envariance—entanglement assisted invariance—is a recently discovered symmetry of composite quantum systems. We show that thermodynamic equilibrium states are fully characterized by their envariance. In particular, the microcanonical equilibrium of a system S with Hamiltonian HS is a fully energetically degenerate quantum state envariant under every unitary transformation. The representation of the canonical equilibrium then follows from simply counting degenerate energy states. Our conceptually novel approach is free of mathematically ambiguous notions such as ensemble, randomness, etc., and, while it does not even rely on probability, it helps to understand its role in the quantum world.8 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Public Domain Mark 1.0This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Lawhttp://creativecommons.org/publicdomain/mark/1.0/Text