Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 50: Correlated Electrons: Frustrated Magnets - Low-Dimensional Systems
TT 50.1: Vortrag
Mittwoch, 22. März 2017, 15:00–15:15, HSZ 304
Quantum Monte Carlo simulations of a frustrated ladder in the dimer basis — •Andreas Honecker1 and Stefan Wessel2 — 1Laboratoire de Physique Théorique et Modélisation, CNRS UMR 8089, Université de Cergy-Pontoise, France — 2Institut für Theoretische Festkörperphysik, RWTH Aachen University, Germany
Frustrated quantum spin systems are notorious for the infamous “sign problem” that prohibits efficient Quantum Monte Carlo simulations in relevant temperature regions. However, the sign problem is basis dependent. Indeed, recent works [1,2] have shown that passing to a rung-dimer basis eliminates the sign problem for the case of a highly frustrated two-leg spin-1/2 ladder where diagonal couplings are equal to the leg couplings. Here we generalise this result to the case where the two couplings along the legs remain antiferromagnetic but are in general different. We find that although the sign problem re-appears in general, it remains sufficiently mild throughout the phase diagram of the frustrated ladder such that efficient Quantum Monte Carlo simulations can be performed, yielding accurate results for thermodynamic quantities such as magnetic susceptibility and specific heat.
[1] A. Honecker, S. Wessel, R. Kerkdyk, T. Pruschke, F. Mila, B. Normand, Phys. Rev. B 93 (2016) 054408
[2] F. Alet, K. Damle, S. Pujari, Phys. Rev. Lett. 117 (2016) 197203