Hybridization wave as the 'Hidden Order' in URu$_2$Si$_2$

TL;DR

This paper proposes a phenomenological model where the hidden order in URu$_2$Si$_2$ is an incommensurate hybridization wave between bands, explaining experimental observations and predicting new testable features.

Contribution

It introduces a hybridization wave as the hidden order parameter in URu$_2$Si$_2$, linking experimental results with a new theoretical framework.

Findings

Identification of incommensurate hybridization as hidden order

Reproduction of gap-like features in density of states

Prediction of incommensurate wave vector Q*~0.6 π/a_0

Abstract

A phenomenological model for the 'hidden order' transition in the heavy Fermion material URu$_2$Si$_2$ is introduced. The 'hidden order' is identified as an incommensurate, momentum-carrying hybridization between the light hole band and the heavy electron band. This modulated hybridization appears after a Fano hybridization at higher temperatures takes place. We focus on the hybridization wave as the order parameter in URu$_2$Si$_2$ and possibly other materials with similar band structures. The model is qualitatively consistent with numerous experimental results obtained from e.g. neutron scattering and scanning tunneling microscopy. Specifically, we find a gap-like feature in the density of states and the appearance of features at an incommensurate vector $Q^*\sim 0.6 \pi/a_0$. Finally, the model allows us to make various predictions which are amenable to current experiments.