Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 23: CE: Quantum-Critical Phenomena 2

TT 23.6: Vortrag

Dienstag, 15. März 2011, 12:00–12:15, HSZ 105

Electron self-energy near a nematic quantum critical point — •Markus Garst¹ and Andrey V. Chubukov² — ¹Institut für Theoretische Physik, Universität zu Köln, 50937 Köln — ²Department of Physics, University of Wisconsin, Madison, 1150 University Avenue, Madison, Wisconsin 53706-1390, USA

We consider an isotropic Fermi liquid in two dimensions near a nematic instability in the charge channel [1]. Previous studies have found that such a system exhibits multiscale quantum criticality with two different energy scales associated with the different dynamics of the two polarization of the nematic order parameter [2]. We study the impact of the multiple energy scales on the electron Green’s function. Apart from the common singular local self-energy of non-Fermi liquid form, we also find a logarithmically singular renormalizations of the quasiparticle residue Z and the vertex Γ. We derive and solve renormalization-group equations for the flow of Z and Γ , and show that the system develops an anomalous dimension at the nematic quantum critical point. As a result, the spectral function at a fixed ω and varying k has a non-Lorentzian form.
M. Garst and A. V. Chubukov, Phys. Rev. B 81, 235105 (2010)
M. Zacharias. P. Wölfle, and M. Garst, Phys. Rev. B 80, 165116 (2009)