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TT: Fachverband Tiefe Temperaturen
TT 29: Frustrated Magnets: General
TT 29.10: Vortrag
Mittwoch, 29. März 2023, 12:00–12:15, HSZ 201
Ground-state degeneracy and magneto-thermodynamics of the spin-1/2 Heisenberg antiferromagnet on the diamond-decorated square lattice — •Andreas Honecker1, Nils Caci2, Taras Verkholyak3, Katarína Karl’ová4, Stefan Wessel2, and Jozef Strečka4 — 1Laboratoire de Physique Théorique et Modélisation, CNRS UMR 8089, CY Cergy Paris Université, France — 2Institute for Theoretical Solid State Physics, RWTH Aachen University, Germany — 3Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, L’viv, Ukraine — 4Department of Theoretical Physics and Astrophysics, P.J. Šafárik University, Košice, Slovakia
The spin-1/2 Heisenberg antiferromagnet on the diamond-decorated square lattice exhibits a rich ground-state phase diagram in a magnetic field [1]. We investigate the thermodynamic properties of this model using a combination of analytical and numerical methods, including full diagonalization up to effectively N=30 sites. We focus in particular on the vicinity of a “dimer-tetramer” phase at low magnetic fields that maps to a classical dimer model on the square lattice and retains a macroscopic ground-state ddegeneracy in a magnetic field. We discuss the consequences of this degeneracy for the thermodynamic and magnetocaloric properties of the system.
[1] N. Caci, K. Karlova, T. Verkholyak, J. Strečka, S. Wessel, A. Honecker, preprint arXiv:2210.15330