The square-kagome quantum Heisenberg antiferromagnet at high magnetic fields: the localized-magnon paradigm and beyond

Автор(и)

  • Oleg Derzhko Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine 1 Svientsitskii Str., L'viv-11, 79011, Ukraine
  • Johannes Richter Institut für Theoretische Physik, Otto-von-Guericke-Universität Magdeburg P.O. Box 4120, D-39016 Magdeburg, Germany
  • Olesia Krupnitska Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine 1 Svientsitskii Str., L'viv-11, 79011, Ukraine
  • Taras Krokhmalskii Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine 1 Svientsitskii Str., L'viv-11, 79011, Ukraine

DOI:

https://doi.org/10.1063/1.4881184%20

Ключові слова:

quantum Heisenberg antiferromagnet, square-kagome lattice, localized magnons, Berezinskii–Kosterlitz–Thouless transition.

Анотація

We consider the spin-1/2 antiferromagnetic Heisenberg model on the two-dimensional square-kagome lattice with almost dispersionless lowest magnon band. For a general exchange coupling geometry we elaborate low-energy effective Hamiltonians which emerge at high magnetic fields. The effective model to describe the low-energy degrees of freedom of the initial frustrated quantum spin model is the (unfrustrated) square-lattice spin-1/2 XXZ model in a z-aligned magnetic field. For the effective model we perform quantum Monte Carlo simulations to discuss the low-temperature properties of the square-kagome quantum Heisenberg antiferromagnet at high magnetic fields. We pay special attention to a magnetic-field driven Berezinskii–Kosterlitz–Thouless phase transition which occurs at low temperatures.

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Опубліковано

2014-04-15

Як цитувати

(1)
Derzhko, O.; Richter, J.; Krupnitska, O.; Krokhmalskii, T. The Square-Kagome Quantum Heisenberg Antiferromagnet at High Magnetic Fields: The Localized-Magnon Paradigm and Beyond. Fiz. Nizk. Temp. 2014, 40, 662-670.

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Низькотемпературний магнетизм