Related papers: Twisting enabled charge transfer excitons in epita…
Exciton mobility in two-dimensional semiconductors is a key ingredient in materials-based design of optoelectronic functionalities. Monolayer transition metal dichalcogenides (TMDs) set a good test case, with tightly bound excitons and…
Due to recent advances, silicon solar cells are rapidly approaching the Shockley-Queisser limit of 33% efficiency. Quantum Dot (QD) solar cells have the potential to surpass this limit and enable a new generation of photovoltaic…
In stark contrast to the conventional charge density wave (CDW) materials, the one-dimensional CDW on the In/Si(111) surface exhibits immediate damping of the CDW oscillation during the photoinduced phase transition. Here, by successfully…
A chain of cofacial molecules with CN or CNh symmetry supports excitonic states with a screw-like structure. These can be quantified with the combination of an axial wavenumber and an azimuthal winding number. Combinations of these states…
We theoretically investigate the absorption and emission of light carrying orbital angular momentum (twisted-light) by quasi-two-dimensional (disc-shaped) quantum dots in the presence of a static magnetic field. We calculate the transition…
In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons (i.e., bound electron-hole pairs) in CsPbBr3 perovskite nanocrystals (NCs)…
Recent experiments suggest that excitonic degrees of freedom play an important role in precipitating the charge density wave (CDW) transition in $1T$-$\mathrm{TiSe}_2$. Through systematic calculations of the electronic and phonon spectrum…
Transition metal dichalcogenide (TMDC) monolayer has recently emerged as an important two-dimensional semiconductor with promising potentials for electronic and optoelectronic devices. Unlike semi-metallic graphene, layered TMDC has a…
Mott insulators sometimes show dramatic changes in their electronic states after photoirradiation, as indicated by photoinduced Mott-insulator-to-metal transition. In the photoexcited states of Mott insulators, electron wavefunctions are…
Excitonic effects due to the correlation of electrons and holes in excited states of matter dominate the optical spectra of many interesting materials. They are usually studied in the long-wavelength limit. Here we investigate excitons at…
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…
Optical processes in insulators and semiconductors, including excitonic effects, can be described in principle exactly using time-dependent density-functional theory (TDDFT). Starting from a linearization of the TDDFT semiconductor Bloch…
In low-dimensional systems with strong electronic correlations, the application of an ultrashort laser pulse often yields novel phases that are otherwise inaccessible. The central challenge in understanding such phenomena is to determine…
Exciton problem is solved in the two-dimensional Dirac model with allowance for strong electron-hole attraction. The exciton binding energy is assumed smaller than but comparable to the band gap. The exciton wavefunction is found in the…
We consider a dynamical phase transition induced by a short optical pulse in a system prone to thermodynamical instability. We address the case of pumping to excitons whose density contributes directly to the order parameter. To describe…
Dipolar bosonic gases are currently the focus of intensive research due to their interesting many-body physics in the quantum regime. Their experimental embodiments range from Rydberg atoms to GaAs double quantum wells and van der Waals…
When a semiconductor absorbs light, the resulting electron-hole superposition amounts to a uncontrolled quantum ripple that eventually degenerates into diffusion. If the conformation of these excitonic superpositions could be engineered,…
Within the Floquet theory of periodically driven quantum systems, we demonstrate that a high-frequency electromagnetic field can be used as an effective tool to control excitonic properties of semiconductor quantum dots (QDs). It is shown,…
Two-dimensional (2D) transition metal dichalcogenides (TMDC) and their moir\'e interfaces have been demonstrated for correlated electron states, including Mott insulators and electron/hole crystals commensurate with moir\'e superlattices.…
We investigate the shift current in two-dimensional (2D) Janus transition-metal dichalcogenides (TMDs). The shift current is evaluated using a real-time approach, where the coupling with an external field is described in terms of a…