Spin dynamics of the 2D spin 1/2 quantum antiferromagnet copper deuteroformate tetradeuterate (CFTD)
The magnetic excitation spectrum in the two-dimensional (2D) S = 1/2 Heisenberg antiferromagnet copper deuteroformate tetradeuterate has been measured for temperatures up to T similar to J/2, where J = 6.31 +/- 0.02 meV is the 2D exchange coupling. For T << J, a dispersion of the zone boundary energy is observed, which is attributed to a wave vector dependent quantum renormalization. At higher temperatures, spin-wavelike excitations persist, but are found to broaden and soften. By combining our data with numerical calculations, and with existing theoretical work, a consistent description of the behavior of the model system is found over the whole temperature interval investigated.
Riso Natl Lab, Condensed Matter Phys & Chem Dept, DK-4000 Roskilde, Denmark. CEA, DRFMC, F-38054 Grenoble, France. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Univ Edinburgh, Dept Chem, Edinburgh EH9 3JJ, Midlothian, Scotland. NEC Res Inst, Princeton, NJ 08540 USA. NORDITA, DK-2100 Copenhagen, Denmark. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Ronnow, HM, Riso Natl Lab, Condensed Matter Phys & Chem Dept, DK-4000 Roskilde, Denmark.
Record created on 2007-01-24, modified on 2016-08-08