Andreev interferometry as a probe of superconducting phase correlations inthe pseudogap regime of the cuprates

Andreev interferometry-the sensitivity of the tunneling current to spatial Variations in the local superconducting order at an interface-is proposed a s a probe of the spatial structure of the phase correlations in the pseudog ap state of the cuprate superconductors. To demonstrate this idea theoretic ally, a simple tunneling model is considered, via which the tunneling curre nt is related to the equilibrium phase-phase correlator in the pseudogap st ate. These considerations suggest that measurement of the low-voltage condu ctance through mesoscopic contacts of varying areas provides a scheme for a ccessing phase-phase correlation information. For illustrative purposes, qu antitative predictions are made for a model of the pseudogap state in which the phase (but not the amplitude) of the superconducting order varies rand omly, and does so with correlations consistent with certain proposed pictur es of the pseudogap state.