Abstract
We present inelastic neutron-scattering data on the quantum paramagnet AgVOAsO4 that establish this system as a S=1/2 alternating spin chain compound and provide a direct measurement of the spin gap Δ=1.2meV. We also present experimental evidence for two different types of field-induced magnetic order between μ0Hc1=8.4T and μ0Hc2=48.9T, which may be related to Bose-Einstein condensation (BEC) of triplons. Thermodynamic measurements in magnetic fields up to 60 T and temperatures down to 0.1 K reveal a H-T phase diagram consisting of a dome encapsulating two ordered phases with maximum ordering temperatures of 3.8 and 5.3 K, respectively. This complex phase diagram is not expected for a single-Q - BEC system and therefore establishes AgVOAsO4 as a promising multi-Q - BEC candidate capable of hosting exotic vortex phases.
| Original language | English |
|---|---|
| Article number | 104422 |
| Journal | Physical Review B |
| Volume | 100 |
| Issue number | 10 |
| DOIs | |
| State | Published - Sep 17 2019 |
Funding
F.W. thanks Cristian D. Batista for fruitful discussions. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory. The National High Magnetic Field Laboratory is supported by the National Science Foundation Cooperative Agreement No. DMR-1157490, the State of Florida, and the United States Department of Energy. N.H. acknowledges support from the following Department of Energy, Basic Energy Science project: Science in 100 Tesla. A.A.T. was supported by the Federal Ministry for Education and Research (Germany) through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation.