Particle-Hole Symmetry Breaking in a Spin-Dimer System TlCuCl3 Observed at 100 T.

The entire magnetization process of TlCuCl3 has been experimentally investigated up to 100 T employing the single-turn technique. The upper critical field Hc2 is observed to be 86.1 T at 2 K. A convex slope of the M-H curve between the lower and upper critical fields (Hc1 and Hc2) is clearly observed, which indicates that a particle-hole symmetry is broken in TlCuCl3. By quantum Monte Carlo simulation and the bond-operator theory method, we find that the particle-hole symmetry breaking results from strong interdimer interactions. [ABSTRACT FROM AUTHOR]