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arXiv · 1711.05438

Thermodynamics of a Quantum Ising system coupled to a spin bath: Zero Temperature Results

R. D. McKenzie·P. C. E Stamp
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Abstract

We study the effect of coupling a spin bath environment to a system which, at low energies, can be modeled as a quantum Ising system. A field theoretic formalism incorporating both thermal and quantum fluctuations is developed to derive results for the thermodynamic properties and response functions, both for a toy model and for the $LiHoF_4$ system, in which spin-8 electronic spins couple to a spin-$7/2$ nuclear spin bath: the phase transition then occurs in a system of electronuclear degrees of freedom, coupled by long-range dipolar interactions. The quantum Ising phase transition still exists, and one hybridized mode of the Ising and bath spins always goes soft at the transition.

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R. D. McKenzie, P. C. E Stamp. 2018-06-04. Thermodynamics of a Quantum Ising system coupled to a spin bath: Zero Temperature Results. https://doi.org/10.1103/physrevb.97.214430

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