The exploration of valley-contrasting physics in two-dimensional materials with strong spin-orbit coupling is of great significance for both fundamental physics and advanced information technology. Here, using first-principles calculations, we report the identification of promising valley-contrasting physics in single-layer CrSiN and CrSiP. Single-layer CrSiN and CrSiP are semiconductors with a direct band gap locating at the K/K' point, which forms a pair of degenerate but nonequivalent valleys in both the conduction and valence bands. These valleys display the intriguing valley spin splitting when considering spin-orbit coupling. Particularly for the valence bands, the valley spin splitting can reach up to 0.13/0.17 eV, giving rise to the robust spin-valley coupling and thus the coexistence of spin and valley Hall effects. The underlying physics are uncovered in detail. Moreover, strain is demonstrated to be an effective way for manipulating their coupled spin and valley physics.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.1c02069 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Quantum Nonlinear Acoustic Hall Effect and Inverse Acoustic Faraday Effect in Dirac Insulators.
Phys Rev Lett
January 2025
Los Alamos National Laboratory, Center for Integrated Nanotechnology, Los Alamos, New Mexico 87545, USA.
We propose to realize the quantum nonlinear Hall effect and the inverse Faraday effect through the acoustic wave in a time-reversal invariant but inversion broken Dirac insulator. We focus on the acoustic frequency much lower than the Dirac gap such that the interband transition is suppressed and these effects arise solely from the intrinsic valley-contrasting band topology. The corresponding acoustoelectric conductivity and magnetoacoustic susceptibility are both proportional to the quantized valley Chern number and independent of the quasiparticle lifetime.
View Article and Find Full Text PDFValley-Contrasting Linear Dichroism and Excitonic Condensation in LaOBiS.
Nano Lett
February 2025
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
In conjunction with the first-principles calculations, we confirm the fascinating valley-selective linear dichroism and the possibility of excitonic condensation in multiatomic-layer LaOBiS of a tetragonal lattice by the effective tight-binding model and many-body perturbation theory. In LaOBiS, which indicates a spontaneous valley polarization due to crystalline symmetry reduction rather than conventional time-reversal symmetry breaking, we unravel that the excitons in X and X' valleys exclusively coupled to - and -linearly polarized lights, respectively. In sharp contrast to coupled quantum wells and van der Waals architectures, a new type of spatially indirect exciton is identified in single-crystal LaOBiS, manifesting itself as an engaging platform for investigating the excitonic Bose-Einstein condensation (BEC) and superfluidity.
View Article and Find Full Text PDFInfluence of resonant plasmonic nanoparticles on optically accessing the valley degree of freedom in 2D semiconductors.
Nat Commun
November 2024
Institute of Solid State Physics, Friedrich Schiller University Jena, 07743, Jena, Germany.
Article Synopsis
- The study examines how valley degrees of freedom in two-dimensional transition metal dichalcogenides, like molybdenum disulfide, could influence future electronic devices.
- Researchers investigate the interaction between valley-specific light emission and a resonant plasmonic nanosphere to understand its effects on circular polarization.
- The findings show unexpected depolarization of light, providing essential insights into light-matter interactions and paving the way for advanced valleytronic device development.
Three-dimensional valley-contrasting sound.
Sci Adv
September 2024
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Spin and valley are two fundamental properties of electrons in crystals. The similarity between them is well understood in valley-contrasting physics established decades ago in two-dimensional (2D) materials like graphene-with broken inversion symmetry, the two valleys in graphene exhibit opposite orbital magnetic moments, similar to the spin-1/2 behaviors of electrons, and opposite Berry curvature that leads to a half topological charge. However, valley-contrasting physics has never been explored in 3D crystals.
View Article and Find Full Text PDFMultiple Valley Modulations in Noncollinear Antiferromagnets.
Nano Lett
September 2024
School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China.
Two-dimensional valleys and magnetism are rising areas with intriguing properties and practical uses in advanced information technology. By coupling valleys to collinear magnetism, valley degeneracy is lifted in a large number of magnetic valley materials to exploit the valley degree of freedom. Beyond collinear magnetism, new coupling modes between valley and magnetism are few but highly desirable.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!