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Pressure-tuned quantum criticality in the large-$D$ antiferromagnet DTN
- Source :
- Nature Communications 15, 2295 (2024)
- Publication Year :
- 2023
-
Abstract
- Strongly correlated spin systems can be driven to quantum critical points via various routes. In particular, gapped quantum antiferromagnets can undergo phase transitions into a magnetically ordered state with applied pressure or magnetic field, acting as tuning parameters. These transitions are characterized by $z=1$ or $z=2$ dynamical critical exponents, determined by the linear and quadratic low-energy dispersion of spin excitations, respectively. Employing high-frequency susceptibility and ultrasound techniques, we demonstrate that the tetragonal easy-plane quantum antiferromagnet NiCl$_{2}\cdot$4SC(NH$_2$)$_2$ (aka DTN) undergoes a spin-gap closure transition at about $4.2$ kbar, resulting in a pressure-induced magnetic ordering. The studies are complemented by high-pressure-electron spin-resonance measurements confirming the proposed scenario. Powder neutron diffraction measurements revealed that no lattice distortion occurs at this pressure and the high spin symmetry is preserved, establishing DTN as a perfect platform to investigate $z=1$ quantum critical phenomena. The experimental observations are supported by DMRG calculations, allowing us to quantitatively describe the pressure-driven evolution of critical fields and spin-Hamiltonian parameters in DTN.<br />Comment: Main text: 9 pages, 7 figures. Supplemental Material: 8 pages, 6 figures
- Subjects :
- Condensed Matter - Strongly Correlated Electrons
Subjects
Details
- Database :
- arXiv
- Journal :
- Nature Communications 15, 2295 (2024)
- Publication Type :
- Report
- Accession number :
- edsarx.2306.15450
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1038/s41467-024-46527-x