Abstract
An external magnetic field can induce a transition in α-RuCl3 from an ordered zigzag state to a disordered state that is possibly related to the Kitaev quantum spin liquid. Here, we present field-dependent inelastic neutron scattering and magnetocaloric effect measurements implying the existence of an additional transition out of the quantum spin-liquid phase at an upper field limit Bu. The neutron scattering shows three distinct regimes of magnetic response. In the low-field ordered state the response shows magnon peaks; the intermediate-field regime shows only continuum scattering, and above Bu the response shows sharp magnon peaks at the lower bound of a strong continuum. Measurable dispersion of magnon modes along the (0,0,L) direction implies non-negligible interplane interactions. Combining the magnetocaloric effect measurements with other data, a T-B phase diagram is constructed. The results constrain the range where one might expect to observe quantum spin-liquid behavior in α-RuCl3.
| Original language | English |
|---|---|
| Article number | 060405 |
| Journal | Physical Review B |
| Volume | 100 |
| Issue number | 6 |
| DOIs | |
| State | Published - Aug 12 2019 |
Funding
We thank M. Meisel and S. Kivelson for valuable discussions. P.L.-K. and D.M. acknowledge support from the Gordon and Betty Moore Foundation's EPiQS Initiative Grant No. GBMF4416. We acknowledge support from the U.S. Department of Energy (U.S.-DOE), Office of Science - Basic Energy Sciences (BES), Materials Sciences and Engineering Division. Work at the Oak Ridge National Laboratory Spallation Neutron Source was supported by U.S.-DOE, Office of Science - BES, Scientific User Facilities Division. We thank the Helmholtz-Zentrum Berlin for the allocation of neutron beamtime. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by the National Science Foundation Cooperative Agreement No. DMR-1644779 and the State of Florida.