Regensburg 2019 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 33: Frustrated Magnets - General 2 (joint session TT/MA)

TT 33.4: Talk

Tuesday, April 2, 2019, 14:45–15:00, Theater

Doping a 2d Mott insulator - Study of a quantum dimer model — •Sebastian Huber¹, Fabian Grusdt^2,3, and Matthias Punk¹ — ¹Arnold Sommerfeld Center, Ludwig-Maximilians University, 80333 Munich, Germany — ²Department of Physics, Harvard University, Cambridge, MA 02138, USA — ³Department of Physics and Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany

Experiments with quantum gas microscopes have started to explore the antiferromagnetic phase of the Fermi-Hubbard model and effects of doping with holes away from half filling [1]. We show in this talk that the system averaged local two-spin density matrix enables to distinguish magnetically ordered and interesting topologically ordered spin-liquid phases, which might occur in the Hubbard model close to half filling.

Fractionalized Fermi liquids (FL*) are a promising candidate for this parameter regime. The generalized quantum dimer model introduced in Ref. [2] is an effective lattice realization of such an FL* with a Hilbert space spanned by configurations of fermionic and bosonic short-range bound states. We construct a rather unconventional dynamical cluster approximation (DCA) by making explicit use of the dimer Hilbert space and show first results of spectral data for a minimal cluster of two lattice sites.
A. Mazurenko, C. Chiu et al., Nature 545, 7655 (2017)
M. Punk, A. Allais and S. Sachdev, PNAS 112, 31 (2015)