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Related papers: Exciton dynamics in WSe2 bilayers

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We report on the kinetics of a low-temperature gas of indirect excitons in the optically-induced exciton trap. The excitons in the region of laser excitation are found to rapidly -- within 4 ns -- cool to the lattice temperature T = 1.4 K,…

Mesoscale and Nanoscale Physics · Physics 2010-03-22 A. T. Hammack , L. V. Butov , L. Mouchliadis , A. L. Ivanov , A. C. Gossard

We present an exciton/lattice model of the electronic dynamics of primary photoexcitations in a polymeric semiconductor heterojunction which includes both polymer pi-stacking, energetic disorder, and phonon relaxation. Results from our…

Materials Science · Physics 2013-09-26 Eric R. Bittner , Carlos Silva

Raman scattering and photoluminescence (PL) emission are used to investigate a single layer of tungsten disulfide (WS$_{2}$) obtained by exfoliating n-type bulk crystals. Direct gap emission with both neutral and charged exciton…

Mesoscale and Nanoscale Physics · Physics 2013-12-05 A. A. Mitioglu , P. Plochocka , J. N. Jadczak , W. Escoffier , G. L. J. A. Rikken , L. Kulyuk , D. K. Maude

The ultrafast formation of strongly bound excitons in two-dimensional semiconductors provide a rich platform for studying fundamental physics as well as developing novel optoelectronic technologies. While extensive research has explored the…

We present time-resolved and CW optical spectroscopy studies of interlayer excitons (IXs) in 2$H-$ and 3$R-$stacked MoSe$_2$/WSe$_2$ heterobilayers and obtain evidence for the strong participation of hot phonons in the underlying…

Mesoscale and Nanoscale Physics · Physics 2024-07-23 Pedro Soubelet , Alex Delhomme , Andreas V. Stier , Jonathan J. Finley

The dynamics of exciton formation in transition metal dichalcogenides is difficult to measure experimentally, since many momentum-indirect exciton states are not accessible to optical interband spectroscopy. Here, we combine a tuneable…

Exciton binding energy and excited states in monolayers of tungsten diselenide (WSe2) are investigated using the combined linear absorption and two-photon photoluminescence excitation spectroscopy. The exciton binding energy is determined…

Materials Science · Physics 2015-06-19 Keliang He , Nardeep Kumar , Liang Zhao , Zefang Wang , Kin Fai Mak , Hui Zhao , Jie Shan

Spintronic terahertz emitters (STEs) pumped by femtosecond lasers have become a widely used source of broadband terahertz radiation. However, the strength of the emitted field is limited in part by the optical damage threshold at the pump…

We describe an experimental system that allows one to easily access the dispersion curve of exciton-polaritons in a microcavity. Our approach is based on two spatial light modulators (SLM), one for changing the excitation angles (momenta),…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 P. Mai , B. Pressl , M. Sassermann , Z. Vörös , G. Weihs , C. Schneider , A. Löffler , S. Höfling , A. Forchel

We present a time-resolved angle-resolved photoelectron spectroscopy study of IrTe$_2$, which undergoes two first-order structural and charge-ordered phase transitions on cooling below 270 K and below 180 K. The possibility of inducing a…

Strongly Correlated Electrons · Physics 2018-03-14 C. Monney , A. Schuler , T. Jaouen , M. -L. Mottas , Th. Wolf , M. Merz , M. Muntwiler , L. Castiglioni , P. Aebi , F. Weber , M. Hengsberger

The effect of an external electric field F on the excitonic photoluminescence (PL) spectra of a symmetric coupled double quantum well (DQW) is investigated both theoretically and experimentally. We show that the variational method in a…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 J. Soubusta , R. Grill , P. Hlidek , M. Zvara , L. Smrcka , S. Malzer , W. Geisselbrecht , G. H. Dohler

Recent experiments on two-dimensional exciton systems have shown the excitons collect in shallow in-plane traps. We find that Bose condensation in a trap results in a dramatic change of the exciton photoluminescence (PL) angular…

Condensed Matter · Physics 2007-05-23 Jonathan Keeling , L. S. Levitov , P. B. Littlewood

Photoluminescence excitation spectroscopy has revealed a novel, highly efficient two-photon excitation method to produce a cold, uniformly distributed high density excitonic gas in bulk cuprous oxide. A study of the time evolution of the…

Strongly Correlated Electrons · Physics 2007-05-23 K. Karpinska , M. Mostovoy , M. A. van der Vegte , A. Revcolevschi , P. H. M. van Loosdrecht

Using first-principles simulations combined with many-body calculations, we show that two-dimensional free-standing quintuple-layer Bi2Se2Te is an inversion symmetric monolayer expected to achieve spatially indirect exciton with large…

Materials Science · Physics 2024-07-18 Yuanyuan Wang , Ying Dai , Baibiao Huang , Yee Sin Ang , Wei Wei

The origin of the charge density wave (CDW) phase in TiSe$_2$ is a highly debated topic, with lattice and excitonic correlations proposed as the main driving mechanisms. One of the proposed scenarios is the excitonic insulator (EI)…

Strongly Correlated Electrons · Physics 2026-02-25 Dino Novko

By implementing four-wave mixing (FWM) micro-spectroscopy we measure coherence and population dynamics of the exciton transitions in monolayers of MoSe$_2$. We reveal their dephasing times T$_2$ and radiative lifetime T$_1$ in a…

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

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…

Here, we report the full-fledged journey towards the material synthesis and characterization of few-layered/thin WSe$_2$ using sputtered W-films on SiO$_2$/Si substrates followed by electrical studies under dark and illumination conditions.…

Monolayers of transition metal dichalcogenides (TMDCs), known for their strong excitonic states with high binding energies in the visible spectrum at room temperature, offer great potential for polariton-driven devices. While polariton…

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