Oliver DeWolfe, Steven S. Gubser, Christopher Rosen
We investigate and classify Fermi surface behavior for a set of fermionic modes in a family of backgrounds holographically dual to N=4 Super-Yang-Mills theory at zero temperature with two distinct chemical potentials. We numerically solve fluctuation equations for every spin-1/2 field in five-dimensional maximally supersymmetric gauged supergravity not mixing with gravitini. Different modes manifest two, one or zero Fermi surface singularities, all associated to non-Fermi liquids, and we calculate dispersion relations and widths of excitations. We study two limits where the zero-temperature entropy vanishes, including one where a Fermi surface approaches a marginal Fermi liquid, which we demonstrate analytically. These limits are gapped, and a conductivity calculation shows in each case the current dual to the active gauge field is superconducting, while the other is insulating.
View original:
http://arxiv.org/abs/1207.3352
No comments:
Post a Comment