Quantum Phase Transitions Without Thermodynamic Limits

Brody, D C; Hook, D W and Hughston, L P. 2007. Quantum Phase Transitions Without Thermodynamic Limits. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 463(2084), pp. 2021-2030. ISSN 1364-5021 [Article]

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Abstract or Description

A new microcanonical equilibrium state is introduced for quantum systems with finite-dimensional state spaces. Equilibrium is characterized by a uniform distribution on a level surface of the expectation value of the Hamiltonian. The distinguishing feature of the proposed equilibrium state is that the corresponding density of states is a continuous function of the energy, and hence thermodynamic functions are well defined for finite quantum systems. The density of states, however, is not in general an analytic function. It is demonstrated that generic quantum systems therefore exhibit second-order phase transitions at finite temperatures.

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11 May 2007Accepted
13 June 2007Published Online
8 August 2007Published

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08 Feb 2022 15:40

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08 Feb 2022 23:20

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Yes, this version has been peer-reviewed.



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