Related papers: Gaussian Expansion Method for few-body states in t…
Charged excitons called trions play an important role in the fundamental valley dynamics in the newly emerging 2D semiconductor materials. We used ultrafast pump- probe spectroscopy to study the valley trion dynamics in a MoSe$_2$ monolayer…
The Stochastic Variational Method (SVM) is used to show that the effective mass model correctly estimates the binding energies of excitons and trions, but fails to predict the experimental binding energy of the biexciton. Using…
We derive the boundary conditions for MoS$_2$ and similar transition-metal dichalcogenide honeycomb (2H polytype) monolayers with the same type of $\mathbf{k}\!\cdot\!\mathbf{p}$ Hamiltonian within the continuum model around the K points.…
Transition metal dichalcogenides (TMDs) are regarded as a possible materials platform for quantum information science and related device applications. In TMD monolayers, the dephasing time and inhomogeneity are crucial parameters for any…
The quest for platforms to generate and control exotic excitonic states has greatly benefited from the advent of transition metal dichalcogenide (TMD) monolayers and their heterostructures. Among the unconventional excitonic states,…
Starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs), we construct a four-band Hamiltonian describing interlayer excitons consisting of an electron in one TMD layer and…
We develop a theoretical description of Coulomb interactions between trions (charged excitons) that define a nonlinear optical response in doped two-dimensional semiconductors. First, we formulate a microscopic theory of trion-trion…
Janus monolayer transition metal dichalcogenides, where one of the two chalcogen layers is substituted with a different kind of chalcogen atoms, are pushing the properties of two dimensional materials into new territories. Yet only little…
We derive an analytical expression for $s$-state exciton energies in monolayer transition-metal dichalcogenides (TMDCs): $E_{\text{ns}}=-{\text{Ry}}^*\times P_n/{(n-1/2+0.479\, r^*_0/\kappa)^2}$, $n=1,2,...$, where $r^*_0$ and $\kappa$ are…
Strong Coulomb interactions in low-dimensional quantum materials give rise to emergent bound states such as excitons and trions, which play a central role in correlated electronic phases. In quasi-one-dimensional systems, equilibrium…
Moir\'e superlattices of transition metal dichalcogenide (TMD) heterostructures give rise to rich excitonic phenomena associated with the interlayer twist angle and induced changes in the involved quantum states. Theoretical calculations of…
Low-dimensional (LD) transition metal dichalcogenides (TMDs) in the form of nanoflakes, which consist of one or several layers, are the subject of intensive fundamental and applied research. Due to the size-induced transition from a bulk to…
We report on the exciton and trion density dynamics in a single layer of MoSe$_2$, resonantly excited and probed using three-pulse four-wave mixing (FWM), at temperatures from 300K to 77K . A multi-exponential third-order response function…
We present optimized tight-binding models with atomic orbitals to improve \textit{ab initio} tight-binding models constructed by truncating full density functional theory (DFT) Hamiltonian based on localized orbitals. Retaining qualitative…
We study the impact of a free carrier reservoir on the optical properties of excitonic and trionic complexes in a MoSe$_2$ monolayer at cryogenic temperatures. By applying photodoping via a non-resonant pump laser the electron density can…
In recent years, a lot of scientific research effort has been put forth for the investigation of Transition Metal Dichalcogenides (TMDC) and other Two Dimensional (2D) materials like Graphene, Boron Nitride. Theoretical investigation on the…
Monolayers of transition metal dichalcogenides (TMDCs), known for their strong excitonic states with high binding energies in the visible spectrum at room temperature, offer great potential for polariton-driven devices. While polariton…
Fabricating van der Waals (vdW) bilayer heterostructures (BL-HS) by stacking the same or different two-dimensional (2D) layers, offers a unique physical system with rich electronic and optical properties. Twist-angle between component…
Since the seminal work on MoS2 monolayers, photoexcitation in atomically-thin transition metal dichalcogenides (TMDCs) has been assumed to result in excitons with large binding energies (~ 200-600 meV). Because the exciton binding energies…
Excitation power and energy dependent photoluminescence (PL) and transient absorption spectroscopy (TAS) studies are carried out on chemical vapour deposition (CVD) grown 1L-MoS2 films to understand the process of trion formation. The study…