Unmasking charge transfer in the Misfits: ARPES and ab initio prediction of electronic structure in layered incommensurate systems without artificial strain

TL;DR

This study combines ARPES measurements and ab initio calculations to clarify that large band shifts in incommensurate misfit compounds are due to hybridization changes, not charge transfer, enhancing understanding of their electronic structure.

Contribution

It introduces a specialized ab initio framework for incommensurate systems and challenges the common belief that band shifts are caused by charge transfer.

Findings

Large band shifts are due to hybridization, not charge transfer.

Ab initio predictions align closely with ARPES measurements.

Provides a new approach to analyze incommensurate electronic structures.

Abstract

Common belief is that the large band shifts observed in incommensurate misfit compounds, e.g. (LaSe)1.14(NbSe2)2, are due to interlayer charge transfer. In contrast, our analysis, based on both ARPES measurements and a specialized ab initio framework employing only quantities well defined in incommensurate materials, demonstrates that the large band shifts instead reflect changes in valence band hybridization and interlayer bonding. The strong alignment of our ab initio predictions and ARPES measurements confirms our understanding of the incommensurate electronic structure and charge transfer.