Confinement induced impurity states in spin chains

TL;DR

This paper explores how impurities in spin chains can induce exotic bound states related to confinement physics, revealing new quantum phenomena that can be experimentally observed in quantum simulators.

Contribution

It demonstrates the emergence of impurity-meson bound states in spin chains and analyzes their properties across different confinement regimes, linking impurity physics with confinement phenomena.

Findings

Long-lived impurity-meson bound states observed

Semiclassical descriptions valid in weak confinement

Quantum effects manifest in bound state energy quantization

Abstract

Quantum simulators hold the promise of probing central questions of high-energy physics in tunable condensed matter platforms, for instance the physics of confinement. Local defects can be an obstacle in these setups harming their simulation capabilities. However, defects in the form of impurities can also be useful as probes of many-body correlations and may lead to fascinating new phenomena themselves. Here, we investigate the interplay between impurity and confinement physics in a basic spin chain setup, showing the emergence of new exotic excitations as impurity-meson bound states with a long lifetime. For weak confinement, semiclassical approximations can describe the capture process in a meson-impurity scattering event. In the strong-confining regime, intrinsic quantum effects are visible through the quantization of the emergent bound state energies which can be readily probed in quantum simulators.