Quantum magnets with large single-ion easy-plane anisotropy in transverse magnetic field
Abstract
We discuss low-temperature properties of magnets with integer spin and large single-ion easy-plane 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:
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arXiv e-prints
- Pub Date:
- December 2011
- DOI:
- 10.48550/arXiv.1112.0833
- arXiv:
- arXiv:1112.0833
- Bibcode:
- 2011arXiv1112.0833S
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 7 pages, 4 figures, to appear in JETP Letters