English

A universal black-box quantum Monte Carlo approach to quantum phase transitions

Statistical Mechanics 2026-01-30 v3 Computational Physics Quantum Physics

Abstract

We derive exact, universal, closed-form quantum Monte Carlo estimators for finite-temperature energy susceptibility and fidelity susceptibility, applicable to essentially arbitrary Hamiltonians. Combined with recent advancements in Monte Carlo, our approach enables a black-box framework for studying quantum phase transitions--without requiring prior knowledge of an order parameter or the manual design of model-specific ergodic quantum Monte Carlo update rules. We demonstrate the utility of our method by applying a single implementation to the transverse-field Ising model, the XXZ model, and an ensemble of models related by random unitaries.

Keywords

Cite

@article{arxiv.2408.03924,
  title  = {A universal black-box quantum Monte Carlo approach to quantum phase transitions},
  author = {Nic Ezzell and Lev Barash and Itay Hen},
  journal= {arXiv preprint arXiv:2408.03924},
  year   = {2026}
}

Comments

published version with minor updates