Effect of Dirac Spinons on ARPES signatures of Herbertsmithe

TL;DR

This paper predicts that ARPES measurements on Herbertsmithite, if it hosts a Dirac spin liquid, will show a linear energy dependence in the spectral function near certain wave vectors, providing evidence for spinons.

Contribution

It demonstrates that Dirac spinons in Herbertsmithite produce distinctive ARPES signatures, even with fluctuations, aiding in experimental identification of spinons.

Findings

Electron spectral function shows linear energy dependence near specific wave vectors.

This signature persists even after fluctuations beyond mean field.

Observation of this signature would strongly support the existence of spinons.

Abstract

The spinon continues to be an elusive elementary excitation of frustrated antiferromagnets. To solidify evidence for its existence, we address the question of what will be the Angle Resolved Photoemission Spectroscopy (ARPES) signatures of single crystal samples of Herbertsmithite assuming it is described by the Dirac spin liquid state. In particular, we show that the electron spectral function will have a linear in energy dependence near specific wave vectors and that this dependence is expected even after fluctuations to the mean field values are taken into account. Observation of this unique signature in ARPES will provide very strong evidence for the existence of spinons in greater than one dimension.