# Observation of two types of anyons in the Kitaev honeycomb magnet

## TL;DR

This paper reports the experimental observation of two types of anyons, gauge fluxes and Majorana fermions, in the Kitaev honeycomb magnet $ ext{α}$-RuCl$_3$, confirming fractionalization predicted by the Kitaev model.

## Contribution

The study demonstrates fractionalization into gapped anyons in a real material, showing survival of these excitations under various conditions despite non-Kitaev interactions.

## Key findings

- Majorana fermion contribution scales with the cube of magnetic field
- Finite zero-field gauge-flux gap matches predictions
- Fractionalization persists across a broad temperature and magnetic field range

## Abstract

Quantum spin liquid is a disordered magnetic state with fractional spin excitations. Its clearest example is found in an exactly solved Kitaev honeycomb model where a spin flip fractionalizes into two types of anyons, quasiparticles that are neither fermions nor bosons: a pair of gauge fluxes and a Majorana fermion. Here we demonstrate this kind of fractionalization in the Kitaev paramagnetic state of the honeycomb magnet $\alpha$-RuCl$_3$. The spin-excitation gap measured by nuclear magnetic resonance consists of the predicted Majorana fermion contribution following the cube of the applied magnetic field, and a finite zero-field contribution matching the predicted size of the gauge-flux gap. The observed fractionalization into gapped anyons survives in a broad range of temperatures and magnetic fields despite inevitable non-Kitaev interactions between the spins, which are predicted to drive the system towards a gapless ground state. The gapped character of both anyons is crucial for their potential application in topological quantum computing.