Enhancement of spin propagation due to interlayer exciton condensation

TL;DR

This paper demonstrates that interlayer exciton condensation in a Mott insulator significantly enhances magnetic excitation bandwidths, providing a new way to probe exciton-spin interactions via resonant inelastic X-ray scattering.

Contribution

It reveals the link between exciton superfluid density and magnetic excitation bandwidths, highlighting a novel interaction in strongly correlated systems.

Findings

Triplon bandwidth scales with exciton superfluid density

Enhanced magnetic excitations observed in doped Mott insulators

Resonant inelastic X-ray scattering can measure these effects

Abstract

We show that an interlayer exciton condensate doped into a strongly correlated Mott insulator exhibits a remarkable enhancement of the bandwidth of the magnetic excitations (triplons). This triplon is visible in the dynamical magnetic susceptibility and can be measured using resonant inelastic X-ray scattering. The bandwidth of the triplon scales with the exciton superfluid density, but only in the limit of strong correlations. As such the triplon bandwidth acts as a probe of exciton-spin interactions in the condensate.