Fermi arcs and pseudogap phase in a minimal microscopic model of d-wave superconductivity

Abstract

We conclusively show that a pseudogap state can arise at T>Tc, for reasonable pairing interaction strength, from order parameter fluctuations in a two-dimensional minimal model of d-wave superconductivity. The occurrence of the pseudogap requires neither strong correlation nor the presence of competing order. We study a model with attractive nearest-neighbor interaction and establish our result using a combination of a cluster-based Monte Carlo method for the order parameter field and a twisted-boundary scheme to compute the momentum-resolved spectral function. Apart from a dip in the density of states that characterizes the pseudogap, the momentum and frequency resolution on our effective lattice size ∼160×160 allows two major conclusions: (i) at T<Tc, despite the presence of thermal phase fluctuations, the superconductor has only nodal Fermi points while all non-nodal points on the normal state Fermi surface show a two-peak spectral function with a dip at ω=0, and (ii) for T>Tc, the Fermi points develop into arcs, characterized by a single quasiparticle peak, and the arcs connect up to recover the normal state Fermi surface at a temperature T*>Tc. We show the variation of Tc and T* with coupling strength and provide detailed spectral results at a coupling where T*∼1.5Tc.

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