Journal ArticleDOI
Valley polarization in stacked MoS 2 induced by circularly polarized light
Juan Xia,Xingli Wang,Beng Kang Tay,Beng Kang Tay,Shoushun Chen,Zheng Liu,Zheng Liu,Jiaxu Yan,Jiaxu Yan,Zexiang Shen,Zexiang Shen +10 more
TLDR
In this article, the authors investigated all possible stacking configurations of chemical-vapor-deposition-grown trilayer MoS2 (AAA, ABB, AAB, 3R, ABA, and 3R) and demonstrated new phenomena correlated to this new stacking freedom that otherwise require the application of external electrical or magnetic field.Abstract:
Manipulation of valley pseudospins is crucial for future valleytronics. The emerging transition metal dichalcogenides (TMDs) provide new possibilities for exploring the interplay among the quantum degrees of freedom, including real spin, valley pseudospin, and layer pseudospin. For example, spin–valley coupling results in valley-dependent circular dichroism in which electrons with particular spin (up or down) can be selectively excited by chiral optical pumping in monolayer TMDs, whereas in few-layer TMDs, the interlayer hopping further affects the spin–valley coupling. In addition to valley and layer pseudospins, here we propose a new degree of freedom—stacking pseudospin—and demonstrate new phenomena correlated to this new stacking freedom that otherwise require the application of external electrical or magnetic field. We investigated all possible stacking configurations of chemical-vapor-deposition-grown trilayer MoS2 (AAA, ABB, AAB, ABA, and 3R). Although the AAA, ABA, 3R stackings possess a sole peak with lower degree of valley polarization than that in monolayer samples, the AAB (ABB) stackings exhibit two distinct peaks, one similar to that observed in monolayer MoS2 and an additional unpolarized peak at lower energy. Our findings provide a more complete understanding of valley quantum control for future valleytronics.read more
Citations
More filters
Journal Article
Valley selective optical Stark effect in monolayer WS2
TL;DR: By applying intense circularly polarized light, which breaks time-reversal symmetry, it is demonstrated that the exciton level in each valley can be selectively tuned by as much as 18 meV through the optical Stark effect, which offers a new way to control the valley degree of freedom.
Journal ArticleDOI
Strong coupling and pressure engineering in WSe 2 –MoSe 2 heterobilayers
Juan Xia,Juan Xia,Jiaxu Yan,Jiaxu Yan,Zenghui Wang,Yongmin He,Yongji Gong,Weiqiang Chen,Weiqiang Chen,Tze Chien Sum,Zheng Liu,Pulickel M. Ajayan,Zexiang Shen +12 more
TL;DR: In this paper, a two-step chemical vapour deposition method was used to realize high-quality 2H-stacked WSe2-MoSe2 heterostructures with strong interlayer coupling, and effective tuning of their interlayer interaction by hydrostatic pressure.
Journal Article
Hidden spin polarization in inversion-symmetric bulk crystals
TL;DR: In this paper, it was shown that spin polarization due to spin-orbit coupling requires broken inversion symmetry, rather than global space-group asymmetry, and that a hitherto overlooked form of spin polarization should also exist in centrosymmetric structures.
Journal ArticleDOI
Direct imaging and determination of the crystal structure of six-layered graphdiyne
Chao Li,Xiu-Li Lu,Ying-Ying Han,Shang-Feng Tang,Yi Ding,Ruirui Liu,Haihong Bao,Yuliang Li,Jun Luo,Tong-Bu Lu +9 more
TL;DR: In this paper, the crystal structure of a six-layered graphdiyne nanosheet was directly observed by lowvoltage transmission electron microscopy (TEM) using low current density.
Journal ArticleDOI
Phase evolution of lithium intercalation dynamics in 2H-MoS2
TL;DR: This study deepens the understanding of the phase transition dynamics upon lithium intercalation, which is of great value to possible optoelectronic devices based on the phase engineering of TMDs.
References
More filters
Journal ArticleDOI
QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials
Paolo Giannozzi,Stefano Baroni,Stefano Baroni,Nicola Bonini,Matteo Calandra,Roberto Car,Carlo Cavazzoni,Davide Ceresoli,Guido L. Chiarotti,Matteo Cococcioni,Ismaila Dabo,Andrea Dal Corso,Andrea Dal Corso,Stefano de Gironcoli,Stefano de Gironcoli,Stefano Fabris,Stefano Fabris,Guido Fratesi,Ralph Gebauer,Ralph Gebauer,Uwe Gerstmann,Christos Gougoussis,Anton Kokalj,Michele Lazzeri,Layla Martin-Samos,Nicola Marzari,Francesco Mauri,Riccardo Mazzarello,Stefano Paolini,Alfredo Pasquarello,Lorenzo Paulatto,Lorenzo Paulatto,Carlo Sbraccia,Sandro Scandolo,Sandro Scandolo,Gabriele Sclauzero,Gabriele Sclauzero,Ari P. Seitsonen,Alexander Smogunov,Paolo Umari,Renata M. Wentzcovitch +40 more
TL;DR: QUANTUM ESPRESSO as discussed by the authors is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density functional theory, plane waves, and pseudopotentials (norm-conserving, ultrasoft, and projector-augmented wave).
Journal ArticleDOI
Self-interaction correction to density-functional approximations for many-electron systems
John P. Perdew,Alex Zunger +1 more
TL;DR: In this paper, the self-interaction correction (SIC) of any density functional for the ground-state energy is discussed. But the exact density functional is strictly selfinteraction-free (i.e., orbitals demonstrably do not selfinteract), but many approximations to it, including the local spin-density (LSD) approximation for exchange and correlation, are not.
Journal ArticleDOI
Atomically thin MoS2: a new direct-gap semiconductor
TL;DR: The electronic properties of ultrathin crystals of molybdenum disulfide consisting of N=1,2,…,6 S-Mo-S monolayers have been investigated by optical spectroscopy and the effect of quantum confinement on the material's electronic structure is traced.
Journal ArticleDOI
Spintronics: Fundamentals and applications
TL;DR: Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems as discussed by the authors, where the primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport.
Journal ArticleDOI
Emerging Photoluminescence in Monolayer MoS2
Andrea Splendiani,Liang Sun,Yuanbo Zhang,Tianshu Li,Jonghwan Kim,Chi-Yung Chim,Giulia Galli,Feng Wang,Feng Wang +8 more
TL;DR: This observation shows that quantum confinement in layered d-electron materials like MoS(2), a prototypical metal dichalcogenide, provides new opportunities for engineering the electronic structure of matter at the nanoscale.