Capturing magic angles in twisted bilayer graphene from information theory markers

TL;DR

This paper uses information theory measures such as fidelity susceptibility and entanglement entropy to identify and analyze the critical twist angles in twisted bilayer graphene where zero energy states exhibit high sensitivity.

Contribution

It introduces a novel approach applying information theory markers to detect quantum criticality at magic angles in twisted bilayer graphene.

Findings

Information theory markers effectively identify magic angles.

Zero energy eigenstates show high sensitivity near these angles.

Markers reveal quantum critical behavior in the system.

Abstract

Zero energy eigenstates $\psi_0(\theta)$ of the twisted bilayer graphene Hamiltonian at the Dirac point show a high sensitivity to the twist angle $\theta$ near the magic angles where the effective Fermi velocity vanishes. We use information theory markers, like fidelity-susceptibility and entanglement entropy of the reduced density matrix to the layer sector, to capture this quantum criticality of zero modes at magic twist angles.