Unusual Thermal Hall Effect in a Kitaev Spin Liquid Candidate α -RuCl3
Abstract
The Kitaev quantum spin liquid displays the fractionalization of quantum spins into Majorana fermions. The emergent Majorana edge current is predicted to manifest itself in the form of a finite thermal Hall effect, a feature commonly discussed in topological superconductors. Here we report on thermal Hall conductivity κx y measurements in α -RuCl3 , a candidate Kitaev magnet with the two-dimensional honeycomb lattice. In a spin-liquid (Kitaev paramagnetic) state below the temperature characterized by the Kitaev interaction JK/kB∼80 K , positive κx y develops gradually upon cooling, demonstrating the presence of highly unusual itinerant excitations. Although the zero-temperature property is masked by the magnetic ordering at TN=7 K , the sign, magnitude, and T dependence of κx y/T at intermediate temperatures follows the predicted trend of the itinerant Majorana excitations.
- Publication:
-
Physical Review Letters
- Pub Date:
- May 2018
- DOI:
- 10.1103/PhysRevLett.120.217205
- arXiv:
- arXiv:1709.10286
- Bibcode:
- 2018PhRvL.120u7205K
- Keywords:
-
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 6 pages, 4 figures