English
Related papers

Related papers: Dynamic Valley Polarization in Moire Quantum Dots

200 papers

Dynamical magnetic and nuclear polarization in complex spin systems is discussed on the example of transfer of spin from exciton to the central spin of magnetic impurity in a quantum dot in the presence of a finite number of nuclear spins.…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Ramin M. Abolfath , Anna Trojnar , Bahman Roostaei , Thomas Brabec , Pawel Hawrylak

We demonstrate optical control of the polarization eigenstates of a neutral quantum dot exciton without any external fields. By varying the excitation power of a circularly polarized laser in micro-photoluminescence experiments on…

Dipolaritons are quasiparticles that arise in coupled quantum wells embedded in a microcavity, they are a superposition of a photon, a direct exciton and an indirect exciton. We propose the existence of dipolaritons in a system of two…

Mesoscale and Nanoscale Physics · Physics 2016-11-23 J. S. Rojas-Arias , B. A. Rodríguez , H. Vinck-Posada

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

In monolayers of transition metal dichalcogenides the nonlocal nature of the effective dielectric screening leads to large binding energies of excitons. Additional lateral confinement gives rise to exciton localization in quantum dots. By…

Mesoscale and Nanoscale Physics · Physics 2021-03-16 Anvar S. Baimuratov , Alexander Högele

We suggest a new spin orientation mechanism for localized electrons: $dynamic~electron~spin~polarization~provided~by~nuclear~spin~fluctuations$. The angular momentum for the electrons is gained from the nuclear spin system via the hyperfine…

Mesoscale and Nanoscale Physics · Physics 2020-10-14 D. S. Smirnov , T. S. Shamirzaev , D. R. Yakovlev , M. Bayer

We present the results of a comprehensive magneto-optical characterization of single CdTe quantum dots containing a few Mn2+ ions. We find that some quantum dots exhibit an unexpected evolution of excitonic photoluminescence spectrum with…

Mesoscale and Nanoscale Physics · Physics 2017-01-04 Maciej Koperski , Tomasz Smoleński , Mateusz Goryca , Piotr Wojnar , Marek Potemski , Piotr Kossacki

Indirect excitons in coupled quantum wells have long radiative lifetimes and form a cold quasi-two-dimensional population suitable for studying collective quantum effects. Here we report the observation of the exciton Mott transition from…

Mesoscale and Nanoscale Physics · Physics 2016-10-26 Gabija Kiršanskė , Petru Tighineanu , Raphaël S. Daveau , Javier Miguel-Sánchez , Peter Lodahl , Søren Stobbe

A novel magnetic interference effect is proposed for a neutral, but polarizable exciton in a quantum ring with a finite width. The magnetic interference effect originates from the nonzero dipole moment in the exciton. The ground state of…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 S. E. Ulloa , A. O. Govorov , A. V. Kalameitsev , R. Warburton , K. Karrai

Owing to exchange interaction between the exciton and magnetic ion, a quantum dot embedding a single magnetic ion is a great platform for optical control of individual spin. In particular, a quantum dot provides strong and sharp optical…

Mesoscale and Nanoscale Physics · Physics 2019-08-15 Aleksander Rodek , Tomasz Kazimierczuk , Aleksander Bogucki , Tomasz Smoleński , Wojciech Pacuski , Piotr Kossacki

Valleytronics is rapidly emerging as an exciting area of basic and applied research. In two dimensional systems, valley polarisation can dramatically modify physical properties through electron-electron interactions as demonstrated by such…

We demonstrate an efficient switching between strong and weak exciton-photon coupling regimes in microcavity-embedded asymmetric double quantum wells, controlled by an applied electric field. We show that a fine tuning of the electric field…

Mesoscale and Nanoscale Physics · Physics 2015-11-02 K. Sivalertporn , E. A. Muljarov

We developed a comprehensive theoretical framework focusing on many-body effects of exciton species in monolayer WS$_2$, including bright and dark excitons, and intra- and inter-valley biexcitons, to investigate valley dynamics in monolayer…

Mesoscale and Nanoscale Physics · Physics 2020-04-17 Fanyao Qu , Helena Bragança , Railson Vasconcelos , Fujun Liu , S-J Xie , Hao Zeng

It is well known that electrically neutral excitons can still be affected by crossed electric and magnetic fields that make them move in a direction perpendicular to both fields. We show that a similar effect appears in the absence of…

Mesoscale and Nanoscale Physics · Physics 2021-01-22 V. K. Kozin , V. A. Shabashov , A. V. Kavokin , I. A. Shelykh

Magnetized ferromagnetic disks or wires support strong inhomogeneous fields in their borders. Such magnetic fields create an effective potential, due to Zeeman and diamagnetic contributions, that can localize charge carriers. For the case…

Mesoscale and Nanoscale Physics · Physics 2024-03-08 A. J. Chaves , D. R. da Costa , F. M. Peeters , Nuno M. R. Peres

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

We propose the rotational dynamics of the intralayer and interlayer excitons with their inherent momenta of inertia in the monolayer and bilayer transition metal dichalcogenides, respectively, where the new chirality of exciton is endowed…

Mesoscale and Nanoscale Physics · Physics 2023-10-10 Yu Cui , Xin-Jun Ma , Jia-Pei Deng , Shao-Juan Li , Ran-Bo Yang , Zhi-Qing Li , Zi-Wu Wang

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

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…

We report measurements consistent with the valley Kondo effect in Si/SiGe quantum dots, evidenced by peaks in the conductance versus source-drain voltage that show strong temperature dependence. The Kondo peaks show unusual behavior in a…

Mesoscale and Nanoscale Physics · Physics 2014-07-04 Mingyun Yuan , R. Joynt , Zhen Yang , Chunyang Tang , D. E. Savage , M. G. Lagally , M. A. Eriksson , A. J. Rimberg