Related papers: Hexcitons and oxcitons in monolayer WSe$_2$
Monolayers of transition metal dichalcogenides are ideal materials to control both spin and valley degrees of freedom either electrically or optically. Nevertheless, optical excitation mostly generates excitons species with inherently short…
The emergence of spatial and temporal coherence of light emitted from solid-state systems is a fundamental phenomenon, rooting in a plethora of microscopic processes. It is intrinsically aligned with the control of light-matter coupling,…
With the both spin and valley degrees of freedom, the low-lying excitonic spectra of photo-excited transition-metal dichalcogenide monolayers (TMDC-MLs) are featured by rich fine structures, comprising the intra-valley bright exciton states…
We report experimental observation of 2s exciton radiative emission from monolayer tungsten diselenide, enabled by hexagonal boron nitride protected high-quality samples. The 2s luminescence is highly robust and persists up to 150K,…
Excitons are key to the optoelectronic applications of van der Waals semiconductors with the potential for versatile on-demand tuning of properties. Yet, their electrical manipulation is complicated by their inherent charge neutrality and…
Strong optical nonlinearities play a central role in realizing quantum photonic technologies. In solid state systems, exciton-polaritons, which result from the hybridization of material excitations and cavity photons, are an attractive…
We investigate the spin-valley physics (SVP) in MoSe$_2$/WSe$_2$ heterobilayers under external electric field (EF) and changes of the interlayer distance (ID). We analyze the spin ($S_z$) and orbital ($L_z$) degrees of freedom, and the…
Atomically thin crystals of transition metal dichalcogenides are ideally suited to study the interplay of light-matter coupling, polarization and magnetic field effects. In this work, we investiagte the formation of exciton-polaritons in a…
In a standard semiconductor laser, electrons and holes recombine via stimulated emission to emit coherent light, in a process that is far from thermal equilibrium. Exciton-polariton condensates -- sharing the same basic device structure as…
Bose-Fermi mixtures naturally appear in various physical systems. In semiconductor heterostructures, such mixtures can be realized, with bosons as excitons and fermions as dopant charges. However, the complexity of these hybrid systems…
Just as photons are the quanta of light, plasmons are the quanta of orchestrated charge-density oscillations in conducting media. Plasmon phenomena in normal metals, superconductors and doped semiconductors are often driven by…
Many monolayer transition metal dichalcogenides, including MoS$_2$, MoSe$_2$, WS$_2$, and WSe$_2$, are direct bandgap two-dimensional (2D) semiconductors with sharp optical resonances at excitonic bound state frequencies. Recent experiments…
Monolayer transition metal dichalcogenides (TMDs) possess superior optical properties, including the valley degree of freedom that can be accessed through the excitation light of certain helicity. While WS2 and WSe2 are known for their…
We experimentally demonstrate dressing of the excited exciton states by a continuously tunable Fermi sea of free charge carriers in a monolayer semiconductor. It represents an unusual scenario of two-particle excitations of charged excitons…
Resolving the momentum degree of freedom of excitons - electron-hole pairs bound by the Coulomb attraction in a photoexcited semiconductor, has remained a largely elusive goal for decades. In atomically thin semiconductors, such a…
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…
A new degree of freedom, the valley pseudospin, emerges in atomically thin two-dimensional transition metal dichalcogenides (MX2) and has attracted great scientific interest. The capability to manipulate the valley pseudospin, in analogy to…
We demonstrate robust power- and wavelength-dependent optical bistability in fully suspended monolayers of WSe2 near the exciton resonance. Bistability has been achieved under continuous-wave optical excitation at an intensity level of 10^3…
We report the experimental observation of radiative recombination from Rydberg excitons in a two-dimensional semiconductor, monolayer WSe2, encapsulated in hexagonal boron nitride. Excitonic emission up to the 4s excited state is directly…
Monolayers of transition metal dichalcogenides (TMDs) have recently emerged as a promising optoelectronic platform. To leverage their full potential, however, it is important to understand and engineer the properties of the different…