Quantum-interference-induced pairing in bosonic doped antiferromagnets

TL;DR

This paper uncovers a novel pairing mechanism in bosonic doped antiferromagnets driven by a hidden Berry phase, leading to a pair density wave and supersolid state, with implications for understanding high-temperature superconductivity.

Contribution

It reveals a new pairing mechanism involving a hidden Berry phase in bosonic doped antiferromagnets, distinct from traditional Fermi surface theories.

Findings

Discovery of a pair density wave coexisting with antiferromagnetic order.

Identification of a Berry phase-induced pairing mechanism.

Potential for experimental probing on quantum simulators.

Abstract

The pairing mechanism in doped antiferromagnets is essential for understanding high-temperature superconductivity. In this work, we investigate the pairing mechanism in bosonic doped antiferromagnets via large-scale density matrix renormalization group calculations of the bosonic $t$-$J$ model. We discover a pair density wave (PDW) coexists with the antiferromagnetic (AFM) order forming a ``supersolid'' at small doping. The pairing is attributed to a hidden many-body Berry phase that introduces the sole ``sign problem'' into this bosonic model and imposes quantum phase frustration to the spin-charge interference pattern. Only via tightly pairing of doped holes, can such frustration be most effectively erased in an AFM background. By contrast, the pairing vanishes as the Berry phase is trivialized in the ferromagnetic condensate at larger doping or switched off into the Bose-Hubbard model at large $U$. The present pairing mechanism -- distinct from the conventional mechanisms based on Fermi surface instabilities -- may provide a different perspective and new insights for understanding the complex nature of doped Mott insulators and is promising to be probed on qudit-based quantum simulators such as ultracold Rydberg atom arrays.