Change search
ReferencesLink to record
Permanent link

Direct link
Sign problem in Monte Carlo simulations of frustrated quantum spin systems
2000 (English)In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 62, no 2, 1102-1113 p.Article in journal (Refereed) Published
Abstract [en]

We discuss the: sign problem arising in Monte Carlo simulations of frustrated quantum spin systems. We show that for a class of semifrustrated systems [Heisenberg models with ferromagnetic couplings J(z)(r) < 0 along the; axis and antiferromagnetic couplings J(yx)(r) = -J(z)(r) in the xy plane, for arbitrary distances, 1. the sign problem present for algorithms operating in the z basis can be solved within a recent operator-loop formulation of the stochastic series expansion method [a cluster algorithm for sampling the diagonal matrix elements of the power series expansion of exp(-beta H) to all orders]. The solution relies on the identification of operator loops which change the configuration sign when updated (merons) and is similar to the meron-cluster algorithm recently proposed by Chandrasekharan and Wiese for solving the sign problem fur a class of fermion models [Phys. Rev. Lett. 83, 3116 (1999]. Some important expectation values, e.g., the internal energy, can be evaluated in the subspace with no merons, where the weight function is positive definite. Calculations of other expectation values require sampling of configurations with only a small number of merons (typically zero or two), with an accompanying sign problem which is not serious. We also discuss problems which arise in applying the meron concept to more general quantum spin models with frustrated interactions.

Place, publisher, year, edition, pages
2000. Vol. 62, no 2, 1102-1113 p.
Keyword [en]
fermion systems, lattices, models
URN: urn:nbn:se:kth:diva-19904ISI: 000088190500058OAI: diva2:338596
QC 20100525Available from: 2010-08-10 Created: 2010-08-10Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Henelius, Patrik
In the same journal
Physical Review B Condensed Matter

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 18 hits
ReferencesLink to record
Permanent link

Direct link