Supersolids in confined fermions on one-dimensional optical lattices

TL;DR

This paper demonstrates through quantum Monte Carlo simulations that one-dimensional confined attractive fermions exhibit supersolid behavior characterized by correlated density and pairing functions, with quantum critical properties unaffected by confinement.

Contribution

It reveals that confinement does not break SU(2) symmetry and that supersolid correlations emerge in the one-dimensional attractive fermionic Hubbard model.

Findings

Correlation functions scale with the same exponent under system size increase.

Quantum critical behavior is observed in confined systems.

Supersolid phase characterized by simultaneous density and pairing order.

Abstract

Using quantum Monte Carlo simulations, we show that density-density and pairing correlation functions of the one-dimensional attractive fermionic Hubbard model in a harmonic confinement potential are characterized by the anomalous dimension $K_\rho$ of a corresponding periodic system, and hence display quantum critical behavior. The corresponding fluctuations render the SU(2) symmetry breaking by the confining potential irrelevant, leading to structure form factors for both correlation functions that scale with the same exponent upon increasing the system size, thus giving rise to a (quasi)supersolid.