| Autor: |
Li, Xiang, Cooper, S. E., Krishnadas, A., de la Torre, A., Perry, R. S., Baumberger, F., Silevitch, D. M., Hsieh, D., Rosenbaum, T. F., Feng, Yejun |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Physical Review B 114, L201111 (2021) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.104.L201111 |
| Popis: |
Protected by the interplay of on-site Coulomb interactions and spin-orbit coupling, Sr$_2$IrO$_4$ at high pressure is a rare example of a Mott insulator with a paramagnetic ground state. Here, using optical Raman scattering, we measure both the phonon and magnon evolution in Sr$_2$IrO$_4$ under pressure, and identify three different magnetically-ordered phases, culminating in a spin-disordered state beyond 18 GPa. A strong first-order structural phase transition drives the magnetic evolution at $\sim$10 GPa with reduced structural anisotropy in the IrO$_6$ cages, leading to increasingly isotropic exchange interactions between the Heisenberg spins and a spin-flip transition to $c$-axis-aligned antiferromagnetic order. In the disordered phase of Heisenberg $J_\mathrm{eff}=1/2$ pseudospins, the spin excitations are quasi-elastic and continuous to 10 meV, potentially hosting a gapless quantum spin liquid in Sr$_2$IrO$_4$. |
| Databáze: |
arXiv |
| Externí odkaz: |
|
