Preparation of the spin-Mott state: a spinful Mott insulator of repulsively bound pairs

TL;DR

This paper reports the experimental observation and analysis of a spin-Mott insulator state formed by repulsively bound pairs of bosons with two spin states in an optical lattice, highlighting its stability and potential for quantum state preparation.

Contribution

It introduces the spin-Mott insulator as a novel ground state of bosons with two spins, characterized by repulsively bound pairs and low entropy, advancing quantum simulation techniques.

Findings

The spin-Mott state is an insulator for both spin and charge transport.

Two decay regimes of the state are observed, with one protected by the pairing gap.

The state can be prepared with low entropy for quantum applications.

Abstract

We observe and study a special ground state of bosons with two spin states in an optical lattice: the spin-Mott insulator, a state that consists of repulsively bound pairs which is insulating for both spin and charge transport. Because of the pairing gap created by the interaction anisotropy, it can be prepared with low entropy and can serve as a starting point for adiabatic state preparation. We find that the stability of the spin-Mott state depends on the pairing energy, and observe two qualitatively different decay regimes, one of which exhibits protection by the gap.