Bose Einstein Condensation in a Spin-Orbit Coupled Quantum Dimer Magnet (QDM)
January 9, 2020
Field dependence of the magnetic excitation spectrum (T=50 mK). (a) Zero field gapped spectrum; (b) The gap is closed in the BEC phase just above 0.4 Tesla. (c) At fields above 1.4 T the gap reopens, and the intensity is weaker and redistributed.
Scientific Achievement
It is shown that a small magnetic field induces magnon Bose Einstein condensation (BEC) in the QDM Yb2Si2O7, and a slightly larger field leads to an unusual regime related to the material’s strong spin-orbit coupling (SOC).
Significance and Impact
This study provides a prototypical illustration of how anisotropy arising from strong SOC can lead to new and unexpected collective phenomena even in relatively simple quantum magnetic systems.
Research Details
- Neutron scattering was used to map out the field dependent phase diagram and character of the ground state.
- Magnetization and ultrasound velocity measurements yield additional information
"Novel Strongly Spin-Orbit Coupled Quantum Dimer Magnet: Yb2Si2O7,"
Gavin Hester, H. S. Nair, T. Reeder, D. R. Yahne, T. N. DeLazzer, L. Berges, D. Ziat, J. R. Neilson, A. A. Aczel, G. Sala, J. A. Quilliam, and K. A. Ross
Phys. Rev. Lett. 123, 027201 (2019)
DOI:https://doi.org/10.1103/PhysRevLett.123.027201
Gavin Hester, H. S. Nair, T. Reeder, D. R. Yahne, T. N. DeLazzer, L. Berges, D. Ziat, J. R. Neilson, A. A. Aczel, G. Sala, J. A. Quilliam, and K. A. Ross
Phys. Rev. Lett. 123, 027201 (2019)
DOI:https://doi.org/10.1103/PhysRevLett.123.027201
