Effects of general non-magnetic quenched disorder on a spin-density-wave quantum critical metallic system in two spatial dimension

Abstract

We investigate the effects of general non-magnetic quenched disorder on the two-dimensional spin-density-wave (SDW) quantum critical metallic system using a renormalization group (RG) method. We consider (i) all possible scattering channels by a random charge potential for a fermion field and (ii) a random mass term for a SDW boson order parameter as effects of the non-magnetic quenched disorder. From the one-loop analysis, we find a weakly disordered non-Fermi liquid metallic fixed point (random mass disordered non-Fermi liquid fixed point) when only the random boson mass vertex is considered. However, in the general case where all disorder vertices are considered, it turns out that there is no stable fixed point and the low-energy RG flows are governed by the large random charge potential vertices especially channels in the ‘Direct’ category. Focusing on the physical meanings of the low-energy RG flows, we provide a detailed explanation of the one-loop results. Beyond the one-loop level, we first discuss partial two-loop corrections to the random charge potential vertices. Furthermore, we examine the possibility of different low-energy RG flows compared to that of the one-loop results by considering the two-loop corrections to the random boson mass vertex and, discuss low-energy properties in relation to the random singlet phase. Related to physical properties, we calculate anomalous dimensions of the four superconducting channels in the one-loop level.