Related papers: Highly tunable layered exciton in bilayer WS$_2$: …
Using resonant 2-photon excitation of interlayer electrons in twisted bilayer graphene (tBLG), we resolve photoluminescence (PL) that tunes spectrally with stacking angle, {\theta}. This weak signal is 4- 5$\times$ larger than the…
We revisit low-temperature optical spectra of transition-metal dichalcogenide monolayers and point to a possible crystallization of electrons (or holes) at low to moderate charge densities. To calculate the excitonic spectra under such…
Quantum confining excitons has been a persistent challenge in the pursuit of strong exciton interactions and quantum light generation. Unlike electrons, which can be readily controlled via electric fields, imposing strong nanoscale…
Low-buckled silicene is a prototypical quantum spin Hall insulator with the topological quantum phase transition controlled by an out-of-plane electric field. We show that this field-induced electronic transition can be further tuned by an…
Realizing an excitonic insulator phase from narrow-gap semiconductors remains challenging, as unambiguous experimental signatures are difficult to establish. Ta$_2$NiSe$_5$ has been widely regarded as a leading candidate, yet the nature of…
Twisted van der Waals heterostructures and the corresponding superlattices, moire superlattices, are remarkable new material platforms, in which electron interactions and excited-state properties can be engineered. Particularly, the band…
Strong Coulomb interactions can drive electrons to crystallize into a Wigner lattice. Achieving the bosonic analogue - a crystal of excitons - has remained elusive due to their short lifetimes and weaker interactions. Here, we report the…
Two-dimensional transition metal dichalcogenides (2D TMDCs) are promising candidates for ultra-thin active nanophotonic elements due to the strong tunable excitonic resonances that dominate their optical response. Here we demonstrate…
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…
When the Coulomb repulsion between electrons dominates over their kinetic energy, electrons in two dimensional systems were predicted to spontaneously break continuous translation symmetry and form a quantum crystal. Efforts to observe this…
Monolayer (1L) transition metal dichalcogenides (TMDC) are of strong interest in nanophotonics due to their narrow-band intense excitonic transitions persisting up to room temperature. When brought into resonance with surface plasmon…
Nonlinear optical frequency conversion, in which optical fields interact with a nonlinear medium to produce new field frequencies, is ubiquitous in modern photonic systems. However, the nonlinear electric susceptibilities that give rise to…
Moir\'e superlattices in twisted van der Waals materials constitute a promising platform for engineering electronic and optical properties. However, a major obstacle to fully understanding these systems and harnessing their potential is the…
The monolayer transition metal dichalcogenides are an emergent semiconductor platform exhibiting rich excitonic physics with coupled spin-valley degree of freedom and optical addressability. Here, we report a new series of low energy…
Twisted bilayer structures have emerged as a fascinating arena in condensed matter thanks to their highly tunable physics. The role of spin-orbit coupling (SOC) in twisted bilayers has gained increasing attention due to its potential for…
We study the Stark effect for an exciton confined in a pair of vertically coupled quantum dots. A single-band approximation for the hole and a parabolic lateral confinement potential are adopted which allows for the separation of the…
Electronic and optical excitations in two-dimensional moir\'e systems are uniquely sensitive to local atomic registries, leading to materials- and twist-angle specific correlated electronic ground states with varied degree of localization.…
Singlet fission, a process that splits a singlet exciton into a biexciton, has promise in quantum information. We report time-resolved electron paramagnetic resonance measurements on a molecule, TIPS-BP1$'$, designed to exhibit strongly…
Low dimensional systems with a vanishing band-gap and a large electron-hole interaction have been proposed to be unstable towards exciton formation. As the exciton binding energy increases in low dimension, conventional wisdom suggests that…
Herein, we present an experimental demonstration of the robust exciton-trion polaritons (ETPs) by measuring and simulating the resonance reflectance spectra of various configurational WS2 monolayers with different dielectric screenings.…