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Thermodynamic analogy for quantum phase transitions at zero temperature

Pavel Cejnar·Stefan Heinze·Jan Dobes
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Abstract

We propose a relationship between thermodynamic phase transitions and ground-state quantum phase transitions in systems with variable Hamiltonian parameters. It is based on a link between zeros of the canonical partition function at complex temperatures and exceptional points of a quantum Hamiltonian in the complex-extended parameter space. This approach is applied in the interacting boson model, where it is shown to properly distinguish the first- and second-order phase transitions.

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Pavel Cejnar, Stefan Heinze, Jan Dobes. 2004-06-17. Thermodynamic analogy for quantum phase transitions at zero temperature. https://doi.org/10.1103/physrevc.71.011304

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