Related papers: Excitons in nonlinear optical responses: shift cur…
Associating the presence of atomic vacancies to excited-state transport phenomena in two dimensional semiconductors is of emerging interest, and demands detailed understanding of the involved exciton transitions. Here we study the effect of…
Monolayer transition metal dichalcogenide (TMDC) semiconductors exhibit strong excitonic optical resonances which serve as a microscopic, non-invasive probe into their fundamental properties. Like the hydrogen atom, such excitons can…
Engineering and probing excitonic properties at the nanoscale remains a central challenge in quantum photonics and optoelectronics. While exciton confinement via electrical control and strain engineering has been demonstrated in 2D…
Enhanced Coulomb interactions in monolayer transition metal dichalcogenides cause tightly bound electron-hole pairs (excitons) which dominate their linear and nonlinear optical response. The latter includes bleaching, energy…
We report ultrafast pump-probe spectroscopy examining exciton dynamics in atomically thin MoS2. Spectrally- and temporally-resolved measurements are performed to investigate the interaction dynamics of two important direct-gap excitons (A…
The strong excitonic effect in monolayer transition metal dichalcogenide (TMD) semiconductors has enabled many fascinating light-matter interaction phenomena. Examples include strongly coupled exciton-polaritons and nearly perfect atomic…
Excitons in atomically-thin semiconductors necessarily lie close to a surface, and therefore their properties are expected to be strongly influenced by the surrounding dielectric environment. However, systematic studies exploring this role…
Exciton-exciton interactions are key to understanding non-linear optical and transport phenomena in van der Waals heterobilayers, which emerged as versatile platforms to study correlated electronic states. We present a combined…
We investigate the excitonic dynamics in MoSe2 monolayer and bulk samples by femtosecond transient absorption microscopy. Excitons are resonantly injected by a 750-nm and 100-fs laser pulse, and are detected by a probe pulse tuned in the…
The electronic band structure of V$_2$O$_5$ is calculated using an all-electron quasiparticle self-consistent (QS) $GW$ method, including electron-hole ladder diagrams in the screening of $W$. The optical dielectric function calculated with…
Atomically thin two-dimensional crystals have revolutionized materials science. In particular, monolayer transition metal dichalcogenides promise novel optoelectronic applications, due to their direct energy gaps in the optical range. Their…
The optical response of semiconducting monolayer transition-metal dichalcogenides (TMDCs) is dominated by strongly bound excitons that are stable even at room temperature. However, substrate-related effects such as screening and disorder in…
Controlling excitons and their transport in two-dimensional (2D) transition metal dichalcogenides (TMDs) heterostructures is central to advancing photonics and electronics on-chip integration. We investigate the controlled generation and…
Transition metal dichalcogenides (TMDCs) have demonstrated significant potential as versatile quantum materials for light absorption and emission. Their unique properties are primarily governed by exciton-photon interactions, which can be…
Nonlinear optics of semiconductors is an important field of fundamental and applied research, but surprisingly the role of excitons in the coherent processes leading to harmonics generation has remained essentially unexplored. Here we…
Semi-metallic graphene and semiconducting monolayer transition metal dichalcogenides (TMDCs) are the two-dimensional (2D) materials most intensively studied in recent years. Recently, black phosphorus emerged as a promising new 2D material…
We present a theory of optical absorption by interlayer excitons in a heterobilayer formed from transition metal dichalcogenides. The theory accounts for the presence of small relative rotations that produce a momentum shift between…
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…
Two-dimensional (2D) semiconductors are promising candidates for optoelectronic application and quantum information processes due to their inherent out-of-plane 2D confinement. In addition, they offer the possibility of achieving…
We study the equivalence of four different approaches to calculate the excitonic linear and nonlinear optical response of multiband semiconductors. These four methods derive from two choices of gauge, i.e. length and velocity gauges, and…