Dresden 2011 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 9: CE: (General) Theory 1

TT 9.5: Talk

Monday, March 14, 2011, 15:00–15:15, HSZ 201

Lower energy bounds for condensed matter systems — •Robert Hübener, Thomas Barthel, and Jens Eisert — Universität Potsdam

Greens function methods, known e.g. from quantum chemistry, allow to calculate lower energy bounds for bosonic and fermionic models in the thermodynamic limit. In the context of condensed matter physics, they can be used to complement variational methods, e.g. DMRG, which generally provide upper bounds. The tightness of the lower bounds depends on the level of compliance with so called N-representability conditions. In this talk we discuss technical aspects, like the formulation of the optimization problem as a semidefinite program, as well as the underlying issue of N-representability. Applications will be demonstrated.