Институт теоретической физики им. Л.Д. Ландау РАН
L.D. Landau Institute for Theoretical Physics RAS
International conference dedicated to the 100th anniversary of I. M. Khalatnikov
"Quantum Fluids, Quantum Field Theory, and Gravity"

October, 17-20, 2019 Chernogolovka, Russia

Strange metal state near quantum superconductor-metal transition in thin films
Date/Time: 12:10 19-Oct-2019
Abstract:
We develop a theory of quantum $T=0$ phase transition between metal and superconducting (q-SMT) ground states in a two-dimensional metal with frozen-in spatial fluctuations $\delta\lambda(r)$ of the Cooper attraction constant. We show that if the strength of fluctuations $\delta\lambda(r)$ exceeds some critical value, usual mean-field-like scenario of the q-SMT breaks down due to spontaneous
formation of rare local droplets of superconducting phase. We account for the interaction between these droplets by means of a real-space renormalization group (RG) and find that the RG flow near q-SMT is the dual equivalent of the Kosterlitz-Thouless RG. We find that relevant energy/temperature scale drops exponentially upon approach to the q-SMT point. Close to the quantum critical point, in a broad range of low temperatures fluctuations-induced conductivity $\sigma_{fl}$ is nearly $T$-independent. This behaviour reminds a "strange metal" phase, frequently observed near SMT.
Attachments:

Authors
Feigel'man Mikhail V. (Presenter)