Paramagnetic Electronic Structure of CrSBr: Comparison between Ab Initio GW Theory and Angle-Resolved Photoemission Spectroscopy

Marco Bianchi; Swagata Acharya; Florian Dirnberger; Julian Klein; Dimitar Pashov; Kseniia Mosina; Zdenek Sofer; Alexander N. Rudenko; Mikhail I. Katsnelson; Mark van Schilfgaarde; Malte Rösner; Philip Hofmann

doi:10.1103/physrevb.107.235107

arXiv · 2303.01292

Paramagnetic Electronic Structure of CrSBr: Comparison between Ab Initio GW Theory and Angle-Resolved Photoemission Spectroscopy

Marco Bianchi·Swagata Acharya·Florian Dirnberger·Julian Klein·Dimitar Pashov·Kseniia Mosina·Zdenek Sofer·Alexander N. Rudenko·Mikhail I. Katsnelson·Mark van Schilfgaarde·Malte Rösner·Philip Hofmann

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Abstract

We explore the electronic structure of paramagnetic CrSBr by comparative first principles calculations and angle-resolved photoemission spectroscopy. We theoretically approximate the paramagnetic phase using a supercell hosting spin configurations with broken long-range order and applying quasiparticle self-consistent $GW$ theory, without and with the inclusion of excitonic vertex corrections to the screened Coulomb interaction (QS$GW$ and QS$G\hat{W}$, respectively). Comparing the quasi-particle band structure calculations to angle-resolved photoemission data collected at 200 K results in excellent agreement. This allows us to qualitatively explain the significant broadening of some bands as arising from the broken magnetic long-range order and/or electronic dispersion perpendicular to the quasi two-dimensional layers of the crystal structure. The experimental band gap at 200 K is found to be at least 1.51 eV at 200 K. At lower temperature, no photoemission data can be collected as a result of charging effects, pointing towards a significantly larger gap, which is consistent with the calculated band gap of $\approx$ 2.1 eV.

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Marco Bianchi, Swagata Acharya, Florian Dirnberger, Julian Klein, Dimitar Pashov, Kseniia Mosina, Zdenek Sofer, Alexander N. Rudenko, Mikhail I. Katsnelson, Mark van Schilfgaarde, Malte Rösner, Philip Hofmann. 2023-03-02. Paramagnetic Electronic Structure of CrSBr: Comparison between Ab Initio GW Theory and Angle-Resolved Photoemission Spectroscopy. https://doi.org/10.1103/physrevb.107.235107

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