DC resistivity of quantum critical, charge density wave states from gauge-gravity duality

In contrast to metals with weak disorder, the resistivity of weakly-pinned charge density waves (CDWs) is not controlled by irrelevant processes relaxing momentum. Instead, the leading contribution is governed by incoherent, diffusive processes which do not drag momentum and can be evaluated in the clean limit. We compute analytically the dc resistivity for a family of holographic charge density wave quantum critical phases and discuss its temperature scaling. Depending on the critical exponents, the ground state can be conducting or insulating. We connect our results to dc electrical transport in underdoped cuprate high $T_c$ superconductors. We conclude by speculating on the possible relevance of unstable, semi-locally critical CDW states to the strange metallic region.