Spin-Triplet Excitons in the $S=1/2$ Gapped Antiferromagnet BaCuSi${}_2$O${}_6$: Electron Paramagnetic Resonance Studies

S. A. Zvyagin, J. Wosnitza, J. Krzystek +4

BaCuSi${}_2$O${}_6$, a $S=1/2$ quantum antiferromagnet with a double-layer structure of Cu${}^{2+}$ ions in a distorted planar-rectangular coordination and with a dimerized spin singlet…