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Related papers: Ultrafast Manipulation of Valley Pseudospin

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A new degree of freedom, the valley pseudospin, emerges in atomically thin two-dimensional transition metal dichalcogenides (MX2) and has attracted great scientific interest. The capability to manipulate the valley pseudospin, in analogy to…

Mesoscale and Nanoscale Physics · Physics 2014-12-10 Jonghwan Kim , Xiaoping Hong , Chenhao Jin , Su-Fei Shi , Chih-Yuan S. Chang , Ming-Hui Chiu , Lain-Jong Li , Feng Wang

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

Two-dimensional transition metal dichalcogenide (TMD) semiconductors provide a unique possibility to access the electronic valley degree of freedom using polarized light, opening the way to valley information transfer between distant…

Due to degeneracies arising from crystal symmetries, it is possible for electron states at band edges ("valleys") to have additional spin-like quantum numbers. An important question is whether coherent manipulation can be performed on such…

Local energy extrema of the bands in momentum space, or valleys, can endow electrons in solids with pseudo-spin in addition to real spin. In transition metal dichalcogenides this valley pseudo-spin, like real spin, is associated with a…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 Grant Aivazian , Zhirui Gong , Aaron M Jones , Rui-Lin Chu , Jiaqiang Yan , David G Mandrus , Chuanwei Zhang , David Cobden , Wang Yao , Xiaodong Xu

Increasing the speed limits of conventional electronics requires innovative approaches to manipulate other quantum properties of electrons besides their charge. An alternative approach utilizes the valley degree of freedom in…

Mesoscale and Nanoscale Physics · Physics 2023-03-29 A. O. Slobodeniuk , P. Koutenský , M. Bartoš , F. Trojánek , P. Malý , T. Novotný , M. Kozák

Strong spin-orbit coupling and inversion symmetry breaking in transition metal dichalcogenide monolayers yield the intriguing effects of valley-dependent optical selection rules. As such, it is possible to substantially polarize valley…

In crystals, energy band extrema in momentum space can be identified by their valley index. The internal quantum degree of freedom associated with valley pseudospin indices can act as a useful information carrier analogous to electronic…

Monolayer valley semiconductors, such as tungsten diselenide (WSe$_2$), possess valley pseudospin degrees of freedom that are optically addressable but degenerate in energy. Lifting the energy degeneracy by breaking time-reversal symmetry…

In monolayers of semiconducting transition metal dichalcogenides, the light helicity ($\sigma^+$ or $\sigma^-$) is locked to the valley degree of freedom, leading to the possibility of optical initialization of distinct valley populations.…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 T. Smoleński , M. Goryca , M. Koperski , C. Faugeras , T. Kazimierczuk , K. Nogajewski , P. Kossacki , M. Potemski

The ability to monitor and control distinct states is at the heart of emerging quantum technologies. The valley pseudospin in transition metal dichalcogenide (TMDC) monolayers is a promising degree of freedom for such control, with the…

The valley pseudospin in monolayer transition metal dichalcogenides (TMDs) has been proposed as a new way to manipulate information in various optoelectronic devices. This relies on a large valley polarization that remains stable over long…

Mesoscale and Nanoscale Physics · Physics 2017-12-22 Fahad Mahmood , Zhanybek Alpichshev , Yi-Hsien Lee , Jing Kong , Nuh Gedik

We apply a microscopic theory of exciton-polaritons in cavity-confined monolayer transition-metal dichalcogenides including both optical polarizations in the monolayer plane, allowing to describe how chiral cavity photons interact with the…

Materials Science · Physics 2021-02-03 Andrew Salij , Roel Tempelaar

Valleytronics, as an alternative to traditional electronics or spintronics, is based on the encoding of quantum information in pseudospin valley quantum numbers, rather than in charge or spin states. A key ingredient is the (optical)…

So far, selective excitation of a desired valley in the Brillouin zone of a hexagonal two-dimensional material has relied on using circularly polarized fields. We theoretically demonstrate a way to induce, control, and read valley…

Optics · Physics 2020-05-21 Álvaro Jiménez-Galán , Rui Silva , Olga Smirnova , Misha Ivanov

Electrons in two-dimensional materials possess an additional quantum attribute, the valley pseudospin, labelled as $\mathbf{K}$ and $\mathbf{K}^{\prime}$ -- analogous to the spin up and spin down. The majority of research to achieve…

Optics · Physics 2023-06-06 Navdeep Rana , Gopal Dixit

The emerging field of valleytronics aims to exploit the valley pseudospin of electrons residing near Bloch band extrema as an information carrier. Recent experiments demonstrating optical generation and manipulation of exciton valley…

Mesoscale and Nanoscale Physics · Physics 2017-05-24 Kai Hao , Lixiang Xu , Fengcheng Wu , Philipp Nagler , Kha Tran , Xin Ma , Christian Schüller , Tobias Korn , Allan H. MacDonald , Galan Moody , Xiaoqin Li

Manipulating and reserving the valley pseudospin of excitons is one core aim in the two-dimensional transition metal dichalcogenides (TMDs). However, due to the strong electron-hole exchange and spin-orbit coupling interactions, the exciton…

Abstract The valley degree of freedom in two-dimensional materials provides an opportunity to extend the functionalities of valleytronics devices. Very short valley lifetimes demand the ultrafast control of valley pseudospin. Here, we…

Spin-valley coupling in monolayer transition metal dichalcogenides gives rise to valley polarization and coherence effect, limited by intervalley scattering caused by exciton-phonon, exciton-impurity, and electron-hole exchange interaction…

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