Continuous similarity transformation for critical phenomena: Easy-axis antiferromagnetic XXZ model
Walther M, Hering DB, Uhrig GS, Schmidt KP (2023)
Publication Type: Journal article
Publication year: 2023
Journal
Book Volume: 5
Journal Issue: 1
DOI: 10.1103/PhysRevResearch.5.013132
Abstract
We apply continuous similarity transformations (CSTs) to the easy-axis antiferromagnetic XXZ model on the square lattice. The CST flow equations are truncated in momentum space by the scaling dimension d so that all contributions with d 2 are taken into account. The resulting quartic magnon-conserving effective Hamiltonian is analyzed in the zero-, one-, and two-magnon sector. In this way, a quantitative description of the ground-state energy, the one-magnon dispersion, and its gap as well as of two-magnon bound states is gained for anisotropies ranging from the gapped Ising model to the gapless Heisenberg model. We discuss the critical properties of the gap closing as well as the evolution of the one-magnon roton mininum. The excitation energies of two-magnon bound states are calculated, and their decay into the two-magnon continuum is determined via the inverse participation ratio.
Authors with CRIS profile
Matthias Walther
Professur für Theoretische Physik
Kai Phillip Schmidt
Professur für Theoretische Physik
Additional Organisation(s)
Involved external institutions
Germany (DE)How to cite
APA:
Walther, M., Hering, D.-B., Uhrig, G.S., & Schmidt, K.P. (2023). Continuous similarity transformation for critical phenomena: Easy-axis antiferromagnetic XXZ model. Physical Review Research, 5(1). https://doi.org/10.1103/PhysRevResearch.5.013132
MLA:
Walther, Matthias, et al. "Continuous similarity transformation for critical phenomena: Easy-axis antiferromagnetic XXZ model." Physical Review Research 5.1 (2023).
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