Emergent Hyper-Magic Manifold in Twisted Kitaev Bilayers

TL;DR

This paper predicts a hyper-magic manifold with flat bands and localized spinon states in twisted Kitaev bilayers, suggesting new avenues for experimental exploration of quantum spin liquids.

Contribution

It introduces a mean-field model for twisted Kitaev bilayers, revealing a hyper-magic manifold with flat bands and Kagome-like localization of spinon states.

Findings

Discovery of a hyper-magic manifold with nearly flat bands

Identification of Kagome-like localization of eigenstates

Potential for experimental probing of high-density spinon states

Abstract

Kitaev quantum spin liquids have been the focus of intense research effort thanks to the discovery of various materials (e.g., RuCl3) that approximate their intriguing physics. In this paper we construct a mean-field approximation for a moir`e superlattice emerging in twisted Kitaev bilayers in terms of solutions of commensurate bilayers. We show that the band structure of deconfined spinons, defined on the mini-Brillouin zone of the superlattice, is greatly modified. The system exhibits a hyper-magic manifold: a series of nearly perfectly-flat bands appear at energies above the lowest gap, exhibiting a very large (spinon) density of states that could potentially be probed experimentally. Intriguingly, flat-band eigenstates exhibit a localization akin to wavefunctions of Kagome lattices.