Self-consistent theory for the paramagnetic properties of TlCuCl3 to first order in the high-density 1/z expansion

TY - JOUR

T1 - Self-consistent theory for the paramagnetic properties of TlCuCl3 to first order in the high-density 1/z expansion

AU - Jensen, Jens

PY - 2011/2/11

Y1 - 2011/2/11

N2 - The Cu spins in TlCuCl3 constitute a well-defined dimer system, where the interaction between the dimers is just at the threshold for inducing magnetic order. The leading order effects of the fluctuations on the paramagnetic properties are analyzed in terms of the systematic high-density 1/z expansion. The predictions agree with those derived from the self-consistent RPA theory published in Phys. Rev. BPLRBAQ1098-012110.1103/PhysRevB.80.224419 80, 224419 (2009). Linewidth effects were neglected in the previous theory, whereas the present one accounts for both the energies and the linewidths of the singlet-triplet excitations. These results are found to be in good agreement with experimental observations at zero field. Experimentally, the renormalization effects are enhanced at fields close to the critical one. This is in accord with the predictions, but both theories overestimate the enhancement.

AB - The Cu spins in TlCuCl3 constitute a well-defined dimer system, where the interaction between the dimers is just at the threshold for inducing magnetic order. The leading order effects of the fluctuations on the paramagnetic properties are analyzed in terms of the systematic high-density 1/z expansion. The predictions agree with those derived from the self-consistent RPA theory published in Phys. Rev. BPLRBAQ1098-012110.1103/PhysRevB.80.224419 80, 224419 (2009). Linewidth effects were neglected in the previous theory, whereas the present one accounts for both the energies and the linewidths of the singlet-triplet excitations. These results are found to be in good agreement with experimental observations at zero field. Experimentally, the renormalization effects are enhanced at fields close to the critical one. This is in accord with the predictions, but both theories overestimate the enhancement.

U2 - 10.1103/physrevb.83.064420

DO - 10.1103/physrevb.83.064420

M3 - Journal article

SN - 2469-9950

VL - 83

SP - 064420

JO - Physical Review B

JF - Physical Review B

IS - 6

ER -