Quantum magnets with large singleion easyplane anisotropy in transverse magnetic field
Abstract
We discuss lowtemperature properties of magnets with integer spin and large singleion easyplane anisotropy $D$ in transverse magnetic field $h$. Considering the exchange interaction between spins as a perturbation and using the diagram technique we derive at $h\sim D$ in the first nonvanishing orders of the perturbation theory thermal corrections to the elementary excitation spectrum, magnetization and specific heat. An expression for the boundary $h_{c1}(T)$ is found in the $h$$T$ plane between the paramagnetic phase and that with the long range magnetic order. The effective interaction is derived between bosons near the quantum critical point $h_{c1}(0)$. The proposed theory describes well experimental data obtained in $\rm NiCl_2$$\rm 4SC(NH_2)_2$ (DTN).
 Publication:

arXiv eprints
 Pub Date:
 December 2011
 DOI:
 10.48550/arXiv.1112.0833
 arXiv:
 arXiv:1112.0833
 Bibcode:
 2011arXiv1112.0833S
 Keywords:

 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 7 pages, 4 figures, to appear in JETP Letters