September 6th
when: Thursday 06/09/2018, 10:30
where: KE E-541 (møterom)
speaker: Lefteris Papantonopoulos (National Technical University of Athens)
title: Building a Holographic Superconductor in a Scalar-Tensor Horndeski Theory
abstract:
We study the holographic dual description of a superconductor in which the gravity sector consists of a Maxwell field and a charged scalar field which except its minimal coupling to gravity it is also coupled kinetically to Einstein tensor. In the probe limit we find that as the strength of the new coupling is increased, the critical temperature is lowering, the condensation gap decreases faster than the temperature, the width of the condensation gap is not proportional to the size of the condensate. When the scalar field backreacts to the metric calculating the conductivity with broken translational symmetry we find that near the critical temperature there is a coexistence of phases indicating collective excitations of charge carriers. This behaviour is typical to doped materials with impurities.