The Bulk van der Waals Layered Magnet CrSBr is a Quasi-1D Material

The Bulk van der Waals Layered Magnet CrSBr is a Quasi-1D Material

Klein, Julian (Massachusetts Institute of Technology)
Pingault, B.J. (TU Delft QID/Taminiau Lab; TU Delft QuTech Advanced Research Centre; Harvard School of Engineering and Applied Sciences)
Florian, Matthias (University of Michigan)
Heißenbüttel, Marie Christin (University of Münster)
Steinhoff, Alexander (University of Bremen)
Song, Zhigang (Harvard University)
Torres, Kierstin (Massachusetts Institute of Technology)
Dirnberger, Florian (City College of New York)
Curtis, Jonathan B. (Harvard University; UCLA)

2023

Correlated quantum phenomena in one-dimensional (1D) systems that exhibit competing electronic and magnetic order are of strong interest for the study of fundamental interactions and excitations, such as Tomonaga-Luttinger liquids and topological orders and defects with properties completely different from the quasiparticles expected in their higher-dimensional counterparts. However, clean 1D electronic systems are difficult to realize experimentally, particularly for magnetically ordered systems. Here, we show that the van der Waals layered magnetic semiconductor CrSBr behaves like a quasi-1D material embedded in a magnetically ordered environment. The strong 1D electronic character originates from the Cr-S chains and the combination of weak interlayer hybridization and anisotropy in effective mass and dielectric screening, with an effective electron mass ratio of m_X^e/m_Y^e ∼ 50. This extreme anisotropy experimentally manifests in strong electron-phonon and exciton-phonon interactions, a Peierls-like structural instability, and a Fano resonance from a van Hove singularity of similar strength to that of metallic carbon nanotubes. Moreover, because of the reduced dimensionality and interlayer coupling, CrSBr hosts spectrally narrow (1 meV) excitons of high binding energy and oscillator strength that inherit the 1D character. Overall, CrSBr is best understood as a stack of weakly hybridized monolayers and appears to be an experimentally attractive candidate for the study of exotic exciton and 1D-correlated many-body physics in the presence of magnetic order.

anisotropic dielectric screening
CrSBr
electron−phonon coupling
exciton−phonon coupling
quasi-1D material
van der Waals magnetic semiconductor
van Hove singularity

http://resolver.tudelft.nl/uuid:64ef5c38-edbd-476e-9935-2bef48a97c90

https://doi.org/10.1021/acsnano.2c07316

2023-09-16

1936-0851

ACS Nano (online), 17 (6), 5316-5328

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2023 Julian Klein, B.J. Pingault, Matthias Florian, Marie Christin Heißenbüttel, Alexander Steinhoff, Zhigang Song, Kierstin Torres, Florian Dirnberger, Jonathan B. Curtis, More Authors