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Path integral Monte Carlo study of the interacting quantum double-well model: Quantum phase transition and phase diagram

Dong-Hee Kim·Yu-Cheng Lin·Heiko Rieger
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Abstract

The discrete time path integral Monte Carlo (PIMC) with a one-particle density matrix approximation is applied to study the quantum phase transition in the coupled double-well chain. To improve the convergence properties, the exact action for a single particle in a double well potential is used to construct the many-particle action. The algorithm is applied to the interacting quantum double-well chain for which the zero-temperature phase diagram is determined. The quantum phase transition is studied via finite-size scaling and the critical exponents are shown to be compatible with the classical two-dimensional (2D) Ising universality class -- not only in the order-disorder limit (deep potential wells) but also in the displacive regime (shallow potential wells).

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Dong-Hee Kim, Yu-Cheng Lin, Heiko Rieger. 2007-01-05. Path integral Monte Carlo study of the interacting quantum double-well model: Quantum phase transition and phase diagram. https://doi.org/10.1103/physreve.75.016702

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