Stefan Maier

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While the problem of calculating critical exponents was believed to be
essentially solved by some experts already in the 1980s, this does not
hold true for metallic systems at present. In a recent study of the
spin-fermion model [1], Sur and Lee have found the first renormalization
group fixed point for a quantum-critical metal using an
epsilon-expansion around $d=3$. The critical theory was shown to have a
quasi-local boson and one-dimensional electrons. However, the nature of
potential fixed points in the physical dimensionality $d=2$ and the
values of critical exponents are an important open problem. In this
talk, I will therefore present first attempts to tackle this problem
within a Wilsonian-type renormalization group framework, where modes
with decreasing momenta are integrated out successively.

[1] Sur and Lee, PRB 91, 125136 (2015)

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University of Cologne
Seminar Room 0.03, ETP
Contact: not specified