Regensburg 2004 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 15: Korrelierte Elektronen: Theorie I
TT 15.7: Vortrag
Dienstag, 9. März 2004, 16:00–16:15, H19
Continuous Unitary Transformations: Dynamic Structure Factors at Zero and Finite Temperatures — •Christian Knetter1, Götz S. Uhrig2, and Hans Kroha1 — 1Physikalisches Institut, Universität Bonn, Nussallee 12, D-53115 Bonn — 2Institut für Theoretische Physik, Universität Köln, Zülpicher Str. 77, D-50937 Köln
Continuous Unitary Transformations (CUTs) have been successfully used to quantitatively calculate the zero temperature spectral densities of various experimentally relevant observables for spin systems in one and two dimensions. Here we present results for the dynamic structure factor of the two-dimensional S=1/2 Shastry-Sutherland model. Our theoretical findings are in excellent agreement with recently obtained inelastic neutron scattering data.
The CUTs are constructed such that the resulting effective Hamiltonians conserve suitably defined quasi-particles. This property is exploited to extend the method to finite temperatures. We present results for the temperature dependent spectral densities of a one-dimensional model including two-particle interactions.