Moiré magnetism and moiré excitons in twisted CrSBr bilayers

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 122(1)

Published: Dec. 31, 2024

Moiré excitons and moiré magnetism are essential to semiconducting van der Waals magnets. In this work, we perform a comprehensive first-principles study elucidate the interplay of electronic excitation in twisted magnetic CrSBr bilayers. We predict twist-induced quantum phase transition for interlayer coupling estimate critical twist angle below which with mixed ferromagnetic antiferromagnetic domains could emerge. Localized one-dimensional stable if is become unstable turns antiferromagnetic. Exciton energy modulation by magnons estimated dependence exciton oscillator strength on analyzed. An orthogonally bilayer revealed exhibit layer-dependent, anisotropic optical transitions. Electric field shown induce net moments excitons, endowing them exceedingly long lifetimes. Our work lays foundation using bilayers spintronic, optoelectronic, information applications.

Language: Английский

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Moiré interlayer exciton relative and center of mass motions coupling. Effect on $$1s-np$$ interlayer exciton THz transitions

The European Physical Journal Plus, Journal Year: 2023, Volume and Issue: 138(5)

Published: May 8, 2023

Language: Английский

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Searching for Unconventional Superfluid in Excitons of Monolayer Semiconductors

Physical Review Letters, Journal Year: 2023, Volume and Issue: 131(23)

Published: Dec. 5, 2023

It is well known that two-dimensional (2D) bosons in homogeneous space cannot undergo real Bose-Einstein condensation, and the superfluid to normal phase transition Berezinskii-Kosterlitz-Thouless (BKT) type, associated with vortex--antivortex pair unbinding. Here we point out a 2D bosonic system whose low energy physics goes beyond conventional paradigm of bosons, i.e., intralayer excitons monolayer metal dichalcogenides. With intrinsic valley-orbit coupling valley Zeeman energy, exciton dispersion becomes linear at small momentum, giving rise series novel features. The critical temperature condensation these nonzero, suggesting true long-range order system. Goldstone mode long wavelength has form $ϵ(\mathbit{q})\ensuremath{\sim}\sqrt{q}$, contrast phonon spectrum. vortex deviates from usual logarithmic respect size, but instead an additional term. Superfluid no longer BKT type for size characteristic scale, without discontinuous jump density. recent experimental progress on fluid thermal equilibrium semiconductors, our work points experimentally accessible search unconventional superfluids paradigm.

Language: Английский

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Optical Tunable Moiré Excitons in Twisted Hexagonal GaTe Bilayers

Chinese Physics Letters, Journal Year: 2023, Volume and Issue: 40(6), P. 067801 - 067801

Published: May 1, 2023

Optical fine-tunable layer-hybridized Moiré excitons are highly in demand for emerging many-body states two-dimensional semiconductors. We report naturally confined bright with long lifetimes twisted hexagonal GaTe bilayers, using ab initio perturbation theory and the Bethe–Salpeter equation. Due to hybridization of electrons holes between layers, which enhances brightness excitons, bilayer system becomes attractive optical applications. find that both R H-type stacking superlattices, more than 200 meV lateral quantum confinements occur on exciton energies, results two scenarios: (1) The ground state X A found be trapped at high-symmetry points, opposite electric dipoles R-stacking supercell, forming a honeycomb superlattice nearest-neighbor dipolar attraction. (2) For H-stacking case, is only one point exhibiting triangular superlattice. Our suggest h-GaTe promising systems excitonic devices provide an ideal platform realizing strong correlated Bose–Hubbard physics.

Language: Английский

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Band splitting under strain: A route to broad-spectrum absorption

Materials Today Physics, Journal Year: 2023, Volume and Issue: 39, P. 101286 - 101286

Published: Nov. 18, 2023

Language: Английский

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