Ground-state properties of the one-dimensional Hubbard model with pairing potential

TL;DR

This paper investigates the ground-state phase diagram of a modified one-dimensional Hubbard model with an external pairing potential, revealing distinct Mott, metallic, and superconducting phases through advanced numerical methods.

Contribution

It provides a comprehensive quantitative analysis of the phase diagram using DMRG techniques guided by bosonization, highlighting the effects of pairing potential on phase properties.

Findings

Identified Mott, metallic, and superconducting phases.

Demonstrated the compressible nature of the Mott phase.

Showed the fully gapped spectrum of the superconducting phase.

Abstract

We consider a modification of the one-dimensional Hubbard model by including an external pairing potential. Guided by analytic bosonization results, we quantitatively determine the grand-canonical zero-temperature phase diagram using both finite and infinite density matrix renormalization group algorithm based on the formalism of matrix product states and matrix product operator, respectively. By computing various local quantities as well as the half-system entanglement, we are able to distinguish between Mott, metallic and superconducting phases. We point out the compressible nature of the Mott phase and the fully gapped nature of the many-body spectrum of the superconducting phase, in the presence of explicit U(1)-charge symmetry breaking.