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Related papers: Valley excitons in two-dimensional semiconductors

200 papers

In monolayer transition metal dichalcogenide semiconductors, valley coherence degrades rapidly due to a combination of fast scattering and inter-valley exchange interaction. This leads to a sub-picosecond valley coherence time, making…

Mesoscale and Nanoscale Physics · Physics 2023-07-21 Garima Gupta , Kenji Watanabe , Takashi Taniguchi , Kausik Majumdar

We theoretically studied the exciton geometric structure in layered semiconducting transition metal dichalcogenides. Based on a three-orbital tight-binding model for Bloch electrons which incorporates their geometric structures, an…

Mesoscale and Nanoscale Physics · Physics 2024-03-11 Jianju Tang , Songlei Wang , Hongyi Yu

Monolayers of transition metal dichalcogenides (TMDCs) exhibit an exceptionally strong Coulomb interaction between charge carriers due to the two-dimensional carrier confinement in connection with weak dielectric screening. High densities…

Mesoscale and Nanoscale Physics · Physics 2018-08-08 D. Erben , A. Steinhoff , G. Schönhoff , T. O. Wehling , C. Gies , F. Jahnke

Monolayers of transition metal dichalcogenides (TMDCs) feature exceptional optical properties that are dominated by excitons, tightly bound electron-hole pairs. Forming van der Waals heterostructures by deterministically stacking individual…

Monolayer semiconducting transition metal dichalcogenides possess broken inversion symmetry and strong spin-orbit coupling, which leads to unique spin-valley locking effect. In 2H stacked pristine multilayers, the spin-valley locking yields…

Mesoscale and Nanoscale Physics · Physics 2023-06-07 Yinong Zhang , Chengxin Xiao , Dmitry Ovchinnikov , Jiayi Zhu , Xi Wang , Takashi Taniguchi , Kenji Watanabe , Jiaqiang Yan , Wang Yao , Xiaodong Xu

By enabling control of valley degrees of freedom in transition-metal dichalcogenides, valley-selective circular dichroism has become a key concept in valleytronics. In this manuscript, we show that valley excitons -- bound electron-hole…

Materials Science · Physics 2022-11-21 Fabio Caruso , Maximilian Schebek , Yiming Pan , Cecilia Vona , Claudia Draxl

Transition metal dichalcogenide semiconductors represent elementary components of layered heterostructures for emergent technologies beyond conventional opto-electronics. In their monolayer form they host electrons with quantized circular…

Electron valleys in transition-metal dichalcogenide monolayers drive novel physics and allow designing multifunctional architectures for applications. We propose to manipulate the electron valleys in these systems for spin/valley filter and…

Mesoscale and Nanoscale Physics · Physics 2021-11-15 Ao Zhang , Kaike Yang , Yun Zhang , Anlian Pan , Mingxing Chen

Two-dimensional semiconductors feature valleytronics phenomena due to locking of the spin and momentum valley of the electrons. However, the valley polarization is intrinsically limited in monolayer crystals by the fast intervalley…

Mesoscale and Nanoscale Physics · Physics 2019-07-10 Long Zhang , Rahul Gogna , G. William Burg , Jason Horng , Eunice Paik , Yu-Hsun Chou , Kyounghwan Kim , Emanuel Tutuc , Hui Deng

Monolayer transition metal dichalcogenides feature Coulomb-bound electron-hole pairs (excitons) with exceptionally large binding energy and coupled spin and valley degrees of freedom. These unique attributes have been leveraged for…

Excitons in monolayer transition-metal dichalcogenides (TMDs) have garnered significant attention because of their large binding energies due to weakly screened Coulomb interaction, and direct bandgap at the K/K$^\prime$ point in the…

We theoretically investigated the coupling between the exciton internal and center-of-mass motions in monolayer transition metal dichalcogenides subjected to a periodic electrostatic potential. The coupling leads to the emergence of…

Mesoscale and Nanoscale Physics · Physics 2024-04-16 Fujia Lu , Qianying Hu , Yang Xu , Hongyi Yu

Encoding and manipulating digital information in quantum degrees of freedom is one of the major challenges of today's science and technology. The valley indices of excitons in transition metal dichalcogenides (TMDs) are well-suited to…

The physics of excitons, electron-hole pairs that are bound together by their mutual Coulomb attraction, can to great extent be understood in the framework of the quantum-mechanical hydrogen model. This model has recently been challenged by…

Mesoscale and Nanoscale Physics · Physics 2017-09-15 Maxim Trushin , Mark Oliver Goerbig , Wolfgang Belzig

Monolayer transition metal dichalcogenides, known for exhibiting strong excitonic resonances, constitute a very interesting and versatile platform for investigation of light-matter interactions. In this work we report on a strong coupling…

Mesoscale and Nanoscale Physics · Physics 2019-05-20 M. Król , K. Lekenta , R. Mirek , K. Łempicka , D. Stephan , K. Nogajewski , M. R. Molas , A. Babiński , M. Potemski , J. Szczytko , B. Piętka

Coherent control and manipulation of quantum degrees of freedom such as spins forms the basis of emerging quantum technologies. In this context, the robust valley degree of freedom and the associated valley pseudospin found in…

Mesoscale and Nanoscale Physics · Physics 2022-11-17 Mandeep Khatoniar , Nicholas Yama , Areg Ghazaryan , Sriram Guddala , Pouyan Ghaemi , Kausik Majumdar , Vinod Menon

The robust spin and momentum valley locking of electrons in two-dimensional semiconductors make the valley degree of freedom of great utility for functional optoelectronic devices. Owing to the difference in optical selection rules for the…

We theoretically investigate the chiral topological excitons emerging in the monolayer transition metal dichalcogenides, where a bulk energy gap of valley excitons is opened up by a position dependent external magnetic field. We find two…

Mesoscale and Nanoscale Physics · Physics 2017-03-31 Z. R. Gong , W. Z. Luo , Z. F. Jiang , H. C. Fu

The presence of two spin-split valleys in monolayer (1L) transition metal dichalcogenide (TMD) semiconductors supports versatile exciton species classified by their spin and valley quantum numbers. While the spin-0 intravalley exciton,…

Mesoscale and Nanoscale Physics · Physics 2020-07-22 Yueh-Chun Wu , Sarath Samudrala , Andrew McClung , Takashi Taniguchi , Kenji Watanabe , Amir Arbabi , Jun Yan

Transition metal dichalcogenides (TMDs) are layered materials that have a semiconducting phase with many advantageous optoelectronic properties, including tightly bound excitons and spin-valley locking. In Tungsten-based TMDs, spin and…

Mesoscale and Nanoscale Physics · Physics 2022-04-27 Saroj B. Chand , John M. Woods , Enrique Mejia , Takashi Taniguchi , Kenji Watanabe , Gabriele Grosso