Magnetic field-induced phase transitions in a weakly coupled s = 1/2 quantum spin dimer system Ba$_{3}$Cr$_{2}$O$_{8}$

TL;DR

This study investigates magnetic field-induced phase transitions in Ba$_{3}$Cr$_{2}$O$_{8}$ using various experimental techniques, revealing the nature of its ground state and the influence of Dzyaloshinsky-Moriya interactions.

Contribution

The paper provides a comprehensive characterization of the thermodynamic and quantum phase diagrams of Ba$_{3}$Cr$_{2}$O$_{8}$, highlighting the role of intra-dimer DM interactions.

Findings

Low field paramagnetic ground state is a mixed singlet and S$_z$=0 triplet state.

Presence of intra-dimer Dzyaloshinsky-Moriya interaction with a specific DM vector orientation.

Identification of phase boundaries in the magnetic field-temperature phase diagram.

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.