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Related papers: Hybrid dark excitons in monolayer $\hbox{MoS}_2$

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Excitons are neutral objects, that, naively, should have no response to a uniform, electric field. Could the Berry curvature of the underlying electronic bands alter this conclusion? In this work, we show that Berry curvature can indeed…

Strongly Correlated Electrons · Physics 2021-04-21 Swati Chaudhary , Christina Knapp , Gil Refael

When transition-metal dichalcogenide monolayers lack inversion symmetry, their low-energy single particle spectrum can described by tilted massive Dirac Hamiltonians. The so-called Janus materials fall into that category. Inversion symmetry…

Mesoscale and Nanoscale Physics · Physics 2022-09-15 M. F. C. Martins Quintela , A. T. Costa , N. M. R. Peres

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

In the last decade atomically thin 2D materials have emerged as a perfect platform for studying and tuning light-matter interaction and electronic properties in nanostructures. The optoelectronic properties in layered materials such as…

Mesoscale and Nanoscale Physics · Physics 2024-10-07 Roberto Rosati , Ioannis Paradisanos , Ermin Malic , Bernhard Urbaszek

We report the experimental observation of quadrupolar exciton states in the reflectance contrast spectrum of 2$H$-stacked bilayer MoSe$_2$. The application of a vertical electric field results in a quadratic energy redshift of these…

Excitons in monolayer transition metal dichalcogenides (TMDs) are formed at K and K' points at the boundary of the Brillouin zone. They acquire a valley degree of freedom, which may be used as a complementary platform for information…

Monolayer transition metal dichalcogenides host tightly-bound excitons, which dominate their optoelectronic response even at room temperatures. Light beams are often used to study these materials with the polarization - often termed as the…

Mesoscale and Nanoscale Physics · Physics 2024-03-01 Omadillo Abdurazakov , Chunqiang Li , Yun-Pil Shim

We show that inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides, making possible controls of spin and valley in these 2D materials.…

Mesoscale and Nanoscale Physics · Physics 2012-05-09 Di Xiao , Gui-Bin Liu , Wanxiang Feng , Xiaodong Xu , Wang Yao

We theoretically study the role of the Berry curvature on neutral and charged excitons in two-dimensional transition-metal dichalcogenides. The Berry curvature arises due to a strong coupling between the conduction and valence bands in…

Mesoscale and Nanoscale Physics · Physics 2019-09-25 A. Hichri , S. Jaziri , M. O. Goerbig

The optical properties of transition metal dichalcogenide monolayers are widely dominated by excitons, Coulomb-bound electron-hole pairs. These quasi-particles exhibit giant oscillator strength and give rise to narrow-band, well-pronounced…

Mesoscale and Nanoscale Physics · Physics 2018-07-13 Christian Schneider , Mikhail M. Glazov , Tobias Korn , Sven Höfling , Bernhard Urbaszek

Transition metal dichalcogenide (TMD) monolayers (MLs) exhibit rich photoluminescence spectra associated with interband optical transitions of direct-gap semiconductors. Upon absorption of photons, direct excitons with zero center-of-mass…

Van der Waals heterostructures show fascinating physics including trapped moire exciton states, anomalous moire exciton transport, generalized Wigner crystals, etc. Bilayers of transition metal dichalcogenides (TMDs) are characterized by…

Mesoscale and Nanoscale Physics · Physics 2023-09-25 Giuseppe Meneghini , Marcel Reutzel , Stefan Mathias , Samuel Brem , Ermin Malic

We address the properties of excitons in monolayer MoS$_2$ from a theoretical point of view, showing that low-energy excitonic states occur both at the Brillouin zone center and at the Brillouin-zone corners, that binding energies at the…

Mesoscale and Nanoscale Physics · Physics 2015-02-25 Fengcheng Wu , Fanyao Qu , A. H. MacDonald

Two-dimensional group-VI transition metal dichalcogenide semiconductors, such as MoS2, WSe2 and others, exhibit strong light-matter coupling and possess direct band gaps in the infrared and visible spectral regimes, making them potentially…

Mesoscale and Nanoscale Physics · Physics 2020-03-03 Thomas Mueller , Ermin Malic

Two-dimensional transition metal dichalcogenides (TMDCs) have recently become attractive semiconductor materials for several optoelectronic applications, such as photodetection, light harvesting, phototransistors, light-emitting diodes, and…

Optics · Physics 2018-07-04 Alex Krasnok , Sergey Lepeshov , Andrea Alú

Monolayer transition-metal dichalcogenides (TMDCs) have recently emerged as possible candidates for valleytronic applications, as the spin and valley pseudospin are directly coupled and stabilized by a large spin splitting. In these…

Spectral ordering between dark and bright excitons in transition metal dichalcogenides is of increasing interest for optoelectronic applications. However, little is known about dark exciton energies and their binding energies. We report the…

Materials Science · Physics 2019-09-18 Hongyu Yu , Magdalena Laurien , Zhenpeng Hu , Oleg Rubel

In van der Waals heterostructures of two-dimensional transition-metal dichalcogenides (2D TMDCs) electron and hole states are spatially localized in different layers forming long-lived interlayer excitons. Here, we have investigated, from…

Materials Science · Physics 2020-11-03 Muhammad S. Ramzan , Jens Kunstmann , Agnieszka B. Kuc

Based on \textit{ab initio} screened configuration interaction calculations we find that TiI$_2$ has a bright exciton ground state and identify two key mechanisms that lead to this unprecedented feature among transition metal…

Mesoscale and Nanoscale Physics · Physics 2026-02-09 Franz Fischer , Carl Emil Mørch Nielsen , Marta Prada , Gabriel Bester

Since the discovery of semiconducting monolayer transition metal dichalcogenides, a variety of experimental and theoretical studies have been carried out seeking to understand the intrinsic exciton population decay and valley relaxation…

Mesoscale and Nanoscale Physics · Physics 2016-05-04 Galan Moody , John Schaibley , Xiaodong Xu