Efficient Quantum Monte Carlo simulations of highly frustrated magnets: the frustrated spin-1/2 ladder
Stefan Wessel, B. Normand, Frédéric Mila, Andreas Honecker
SciPost Phys. 3, 005 (2017) · published 18 July 2017
- doi: 10.21468/SciPostPhys.3.1.005
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Abstract
Quantum Monte Carlo simulations provide one of the more powerful and versatile numerical approaches to condensed matter systems. However, their application to frustrated quantum spin models, in all relevant temperature regimes, is hamstrung by the infamous "sign problem." Here we exploit the fact that the sign problem is basis-dependent. Recent studies have shown that passing to a dimer (two-site) basis eliminates the sign problem completely for a fully frustrated spin model on the two-leg ladder. We generalize this result to all partially frustrated two-leg spin-1/2 ladders, meaning those where the diagonal and leg couplings take any antiferromagnetic values. We find that, although the sign problem does reappear, it remains remarkably mild throughout the entire phase diagram. We explain this result and apply it to perform efficient quantum Monte Carlo simulations of frustrated ladders, obtaining accurate results for thermodynamic quantities such as the magnetic specific heat and susceptibility of ladders up to L=200 rungs (400 spins 1/2) and down to very low temperatures.
Cited by 28
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Stefan Wessel,
- 2 Bruce Normand,
- 3 Frédéric Mila,
- 4 5 Andreas Honecker
- 1 Rheinisch-Westfälische Technische Hochschule Aachen / RWTH Aachen University [RWTH]
- 2 Paul Scherrer Institute [PSI]
- 3 École Polytechnique Fédérale de Lausanne [EPFL]
- 4 CY Cergy Paris Université / CY Cergy Paris University
- 5 Centre National de la Recherche Scientifique / French National Centre for Scientific Research [CNRS]