SKM 2023 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 29: Frustrated Magnets: General
TT 29.9: Talk
Wednesday, March 29, 2023, 11:45–12:00, HSZ 201
Phases of the spin-1/2 Heisenberg antiferromagnet on the diamond-decorated square lattice in a magnetic field — •Nils Caci1, Katarína Karl'ová2, Taras Verkholyak3, Jozef Strečka2, Stefan Wessel1, and Andreas Honecker4 — 1Institute for Theoretical Solid State Physics, RWTH Aachen University, Germany — 2Department of Theoretical Physics and Astrophysics, P.J. Šafárik University, Košice, Slovakia — 3Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, L'viv, Ukraine — 4Laboratoire de Physique Théorique et Modélisation, CNRS UMR 8089, CY Cergy Paris Université, France
The spin-1/2 Heisenberg antiferromagnet on the highly frustrated diamond-decorated square lattice is a spin system of orthogonal spin dimers that features various ground-state phases, consisting of extended monomer-dimer and dimer-tetramer ground states as well as a ferrimagnetic regime. By using a combination of density matrix renormalization group (DMRG), exact diagonalization, as well as unbiased sign-problem free quantum Monte Carlo (QMC) methods, we investigate this system in the presence of a finite magnetic field. We find at high magnetic fields the emergence of a spin-canted phase, with continuously rising magnetization, as well as the fully polarized paramagnetic phase. At intermediate field strength, we identify the presence of a first-order quantum phase transition line between a ferrimagnetic phase and the monomer-dimer regime, which extends to finite temperatures and terminates in a line of critical points belonging to the Ising universality class.