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Related papers: Valley depolarization in monolayer WSe2

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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 investigate the valley depolarization dynamics and valley Hall effect of exciton due to the electron-hole exchange interaction in mono- and bilayer MoS$_2$ by solving the kinetic spin Bloch equations. The effect of the exciton energy…

Mesoscale and Nanoscale Physics · Physics 2016-01-15 T. Yu , M. W. Wu

Monolayer transition metal dichalcogenides have attracted great attentions for potential applications in valleytronics. However, the valley polarization degree is usually not high because of the intervalley scattering. Here, we demonstrate…

Materials Science · Physics 2023-02-23 Jianchen Dang , Mingwei Yang , Xin Xie , Zhen Yang , Danjie Dai , Zhanchun Zuo , Can Wang , Kuijuan Jin , Xiulai Xu

We report on the influence of a photochemical doping method on the spin-valley polarization degree ($P_{c}$) of excitons in WSe$_2$ monolayers. By varying the carrier density and transitioning from an excess of electrons (n-type) to an…

Heterostructures comprising different monolayer semiconductors provide a new system for fundamental science and device technologies, such as in the emerging field of valleytronics. Here, we realize valley-specific interlayer excitons in…

Mesoscale and Nanoscale Physics · Physics 2016-01-13 Pasqual Rivera , Kyle L. Seyler , Hongyi Yu , John R. Schaibley , Jiaqiang Yan , David G. Mandrus , Wang Yao , Xiaodong Xu

In this letter, we address the chiral properties of valley exciton-polaritons in a monolayer of WS2 in the regime of strong light-matter coupling with a Tamm-Plasmon resonance. We observe that the valley polarization, which manifests in the…

Mesoscale and Nanoscale Physics · Physics 2017-12-13 N. Lundt , S. Stoll , P. Nagler , A. Nalitov , S. Klembt , S. Betzold , J. W. Goddard , E. Frieling , A. V. Kavokin , C. Schüller , T. Korn , S. Höfling , C. Schneider

We report experimental observation of 2s exciton radiative emission from monolayer tungsten diselenide, enabled by hexagonal boron nitride protected high-quality samples. The 2s luminescence is highly robust and persists up to 150K,…

Mesoscale and Nanoscale Physics · Physics 2018-01-31 Shao-Yu Chen , Thomas Goldstein , Jiayue Tong , Takashi Taniguchi , Kenji Watanabe , Jun Yan

Coupling between exciton states across the Brillouin zone in monolayer transition metal dichalcogenides can lead to ultrafast valley depolarization. Using time- and angle-resolved photoemission, we present momentum- and energy-resolved…

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 transition metal dichalcogenides have emerged as prominent candidates to explore the complex interplay between the spin and the valleys degrees of freedom. The strong spin-orbit interaction and broken inversion symmetry within…

Semiconducting transition metal dichalcogenide monolayers have emerged as promising candidates for future valleytronics-based quantum information technologies. Two distinct momentum-states of tightly-bound electron-hole pairs in these…

Mesoscale and Nanoscale Physics · Physics 2017-03-16 Gerd Plechinger , Tobias Korn , John M. Lupton

Moir\'e superlattices created by stacking atomic layers of transition metal dichalcogenide semiconductors have emerged as a class of fascinating artificial photonic and electronic materials. An appealing attribute of these structures is the…

Mesoscale and Nanoscale Physics · Physics 2025-03-11 Yueh-Chun Wu , Matthew DeCapua , ZhongChen Xu , Takashi Taniguchi , Kenji Watanabe , YouGuo Shi , Jun Yan

The coupling between spin, charge, and lattice degrees of freedom plays an important role in a wide range of fundamental phenomena. Monolayer semiconducting transitional metal dichalcogenides have emerged as an outstanding platform for…

We have investigated the steady-sate valley polarization and valley coherence of encapsulated MoS2 monolayer as a function of the temperature and the power density with a continuous wave laser excitation. Both valley polarization and…

Materials Science · Physics 2021-11-01 Fabian Cadiz , Stefan Gerl , Takashi Taniguchi , Kenji Watanabe

For applications exploiting the valley pseudospin degree of freedom in transition metal dichalcogenide monolayers, efficient preparation of electrons or holes in a single valley is essential. Here, we show that a magnetic field of 7 Tesla…

Mesoscale and Nanoscale Physics · Physics 2017-06-14 Patrick Back , Meinrad Sidler , Ovidiu Cotlet , Ajit Srivastava , Naotomo Takemura , Martin Kroner , Atac Imamoglu

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…

Here, the underlying mechanisms behind valley de-polarization is investigated in chemical vapor deposited 1L-MoS$_{2}$. Temperature dependent polarization resolved photoluminescence spectroscopy was carried out on as-grown, transferred and…

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

Monolayers of transition metal dichalcogenides are ideal materials to control both spin and valley degrees of freedom either electrically or optically. Nevertheless, optical excitation mostly generates excitons species with inherently short…

We measured the lifetime of optically created valley polarization in single layer WS2 using transient absorption spectroscopy. The electron valley relaxation is very short (< 1ps). However the hole valley lifetime is at least two orders of…

Materials Science · Physics 2014-08-06 Cong Mai , Yuriy G. Semenov , Andrew Barrette , Yifei Yu , Zhenghe Jin , Linyou Cao , Ki Wook Kim , Kenan Gundogdu