paper

Heisenberg spin chains with additional isotropic three-site exchange interactions

arXiv:2101.05164 · doi:10.5488/CMP.23.43702

Abstract

The Heisenberg spin models with nearest-neighbor () and additional isotropic three-site () spin interactions remain relatively less explored, although such types of competing exchange terms can naturally emerge from different sources, including the strong-coupling expansion of the multiorbital Hubbard model. Below we present a short survey of the recently published research in this field, the emphasis being on the characteristics of the variety of quantum phases supported by a few generic uniform- and alternating-spin Heisenberg chains. For the reason that the positive () three-site couplings tend towards the formation of local quantum dimers, the spin models typically experience some spontaneous dimerization upon increasing . Actually, it occurred that the established dimer phases in spin- Heisenberg chains () serve as complete analogues of the famous gapped Majumdar-Ghosh dimer phase in the spin- Heisenberg chain with next-nearest-neighbor couplings. The same dimerizations have been observed in the alternating-spin () chains (), provided that the cell spin , whereas for half-integer cell spin, the local dimer formation produces gapless spin-liquid ground states. The alternating-spin chains also provide some typical examples of spin models supporting the so-called non-Lieb-Mattis magnetic phases.

10 pages, 5 figures

References in corpus (10)