# The Spectral Periodicity of Spinon Continuum in Quantum Spin Ice

## TL;DR

This paper investigates the spectral periodicity of spinon excitations in quantum spin ice, linking symmetry fractionalization to observable spectral features, and proposes experimental detection methods via neutron scattering.

## Contribution

It explicitly demonstrates how crystal symmetry fractionalization affects the spectral periodicity of the spinon continuum in U(1) spin liquids, providing a new way to detect fractionalization.

## Key findings

- Spinon excitations form a continuum observable in neutron scattering.
- Spectral periodicity is enhanced when spinons experience a $ ext{pi}$ flux.
- The spectral properties can reveal spin quantum number fractionalization.

## Abstract

Motivated by the rapid experimental progress of quantum spin ice materials, we study the dynamical properties of pyrochlore spin ice in the U(1) spin liquid phases. In particular, we focus on the spinon excitations that appear at high energies and show up as an excitation continuum in the dynamic spin structure factor. The keen connection between the crystal symmetry fractionalization of the spinons and the spectral periodicity of the spinon continuum is emphasized and explicitly demonstrated. When the spinon experiences a background $\pi$ flux and the spinon continuum exhibits an enhanced spectral periodicity with a folded Brillouin zone, this spectral property can then be used to detect the spin quantum number fractionalization and U(1) spin liquid. Our prediction can be immediately examined by inelastic neutron scattering experiments among quantum spin ice materials with Kramers' doublets. Further application to the non-Kramers' doublets is discussed.