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arXiv · 2312.11333

Out-of-equilibrium full counting statistics in Gaussian theories of quantum magnets

Riccardo Senese·Jacob H. Robertson·Fabian H. L. Essler
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Abstract

We consider the probability distributions of the subsystem (staggered) magnetization in ordered and disordered models of quantum magnets in D dimensions. We focus on Heisenberg antiferromagnets and long-range transverse-field Ising models as particular examples. By employing a range of self-consistent time-dependent mean-field approximations in conjunction with Holstein-Primakoff, Dyson-Maleev, Schwinger boson and modified spin-wave theory representations we obtain results in thermal equilibrium as well as during non-equilibrium evolution after quantum quenches. To extract probability distributions we derive a simple formula for the characteristic function of generic quadratic observables in any Gaussian theory of bosons.

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Riccardo Senese, Jacob H. Robertson, Fabian H. L. Essler. 2023-12-18. Out-of-equilibrium full counting statistics in Gaussian theories of quantum magnets. https://doi.org/10.21468/scipostphys.17.5.139

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