Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 56: Correlated Electrons: Quantum-Critical Phenomena – Theory

TT 56.11: Vortrag

Mittwoch, 18. März 2015, 12:15–12:30, A 053

Anomalous dynamical exponent at the Ising-nematic quantum critical point — •Tobias Holder and Walter Metzner — Max-Planck-Institute for Solid State Research, D-70569 Stuttgart, Germany

We present a systematic study of higher order fluctuation corrections for a two-dimensional critical metal at the onset of Ising-nematic order. This type of instability is of interest in the study of competing orders in high-temperature superconductivity and with spin liquids. In the critical regime, strong forward scattering gives rise to non-Fermi liquid behavior with overdamped quasiparticles and a dynamical critical exponent z=3.

Using a renormalization group approach to the spin-fermion model in a two-patch approximation, we analyze the structure of density-density vertices of any order. This allows for a general classification of finite and singular contributions, which reveals a renormalization of z=3 at four loop order. The results are applicable to a wide range of non-Fermi liquids.