Magnetic field-induced phase transitions in a weakly coupled s = 1/2 quantum spin dimer system Ba${}_3$Cr${}_2$O${}_8$

Abstract

By using bulk magnetization, electron spin resonance (ESR), heat capacity, and neutron scattering techniques, we characterize the thermodynamic and quantum phase diagrams of Ba${}_3$Cr${}_2$O${}_8$. Our ESR measurements indicate that the low field paramagnetic ground state is a mixed state of the singlet and the S${}_z$ = 0 triplet for $H\perp c$. This suggests the presence of an intra-dimer Dzyaloshinsky-Moriya (DM) interaction with a DM vector perpendicular to the c-axis.