Holographic superconductivity from higher derivative theory

摘要

We construct a 6 derivative holographic superconductor model in the 4-dimensional bulk spacetimes, in which the normal state describes a quantum critical (QC) phase. The phase diagram ( γ 1 , T ? c ) and the condensation as the function of temperature are worked out numerically. We observe that with the decrease of the coupling parameter γ 1 , the critical temperature T ? c decreases and the formation of charged scalar hair becomes harder. We also calculate the optical conductivity. An appealing characteristic is a wider extension of the superconducting energy gap, comparing with that of 4 derivative theory. It is expected that this phenomena can be observed in the real materials of high temperature superconductor. Also the Homes' law in our present models with 4 and 6 derivative corrections is explored. We find that in certain range of parameters γ and γ 1 , the experimentally measured value of the universal constant C in Homes' law can be obtained.