相关论文: Exciton dynamics and high-temperature excitonic su…
Excitons, the bosonic quasiparticle emerging from Coulomb interaction between electrons and holes, will undergo a Bose-Einstein condensation(BEC) and transition into a superfluid state with global phase coherence at low temperatures. An…
Metal monochalcogenide GaSe is a classic layered semiconductor that has received increasing research interest due to its highly tunable electronic and optical properties for ultrathin electronics applications. Despite intense research…
Biased bilayer graphene (BBG) is a variable band gap semiconductor, with a strongly field-dependent band gap of up to $300 \, \text{meV}$, making it of particular interest for graphene-based nano-electronic and -photonic devices. The…
The search for carbon-based materials with tailored dimensionality and properties remains an important topic in materials science, particularly for applications in electronics, photonics, and nanomechanics. Among the emerging platforms in…
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…
The excitonic spectra of single layer GeS and GeSe are predicted by ab initio GW-Bethe Salpeter equation calculations. G 0 W 0 calculations for the band structures find a fundamental band gap of 2.85 eV for GeS and 1.70 eV for GeSe…
We present first-principles calculations of many-electron effects on the optical response of graphene, bilayer graphene, and graphite employing the GW-Bethe Salpeter equation approach. We find that resonant excitons are formed in these…
The quasiparticle band structure and optical properties of single-walled zigzag and armchair SiC nanotubes (SiC-NTs) as well as single SiC sheet are investigated by ab initio many-body calculations using the GW and the GW plus…
We consider suspened bilayer graphene under applied perpendicular electric bias field that is known to generate a single particle gap $2\Delta$ and a related electric polarization ${\cal P}$. We argue that the bias also drives a quantum…
Spatially indirect excitons can be created when an electron and a hole, confined to separate layers of a double quantum well system, bind to form a composite Boson. Because there is no recombination pathway such excitons are long lived…
Exciton plays an important role in optics and optics-related behaviors and leads to novel correlated phases like charge order, exciton insulator, and exciton-polariton condensation. Dark exciton shows distinct properties from bright one.…
The energy spectra and wavefunctions of bound excitons in important two-dimensional (2D) graphene derivatives, i.e., graphyne and graphane, are found to be strongly modified by quantum confinement, making them qualitatively different from…
We present an alternative methodology for calculating the quasi-particle energy, energy loss, and optical spectra of a molecule deposited on graphene or a metallic substrate. To test the accuracy of the method it is first applied to the…
In this study, we investigate excitonic properties of epitaxially grown WS2, which is of particular interest for various applications due to its potential for upscaling to wafer sized structures. Understanding the effect of the dielectric…
Using Scanning Tunneling Microscopy and Spectroscopy, we probe the electronic structures of single layer ${\small MoS_2}$ on graphite. We show that the quasiparticle energy gap of single layer ${\small MoS_2}$ is 2.15 $\pm$ 0.07 eV at 77 K.…
We investigate excitonic transitions in a h-BN encapsulated monolayer $\textrm{MoS}_2$ phototransistor by photocurrent spectroscopy at cryogenic temperature (T = 5 K). The spectra presents excitonic peaks with linewidths as low as 8 meV,…
We present ab initio many-body calculations of the optical absorption in bulk graphite, graphene and bilayer of graphene. Electron-hole interaction is included solving the Bethe-Salpeter equation on top of a GW quasiparticle electronic…
Spectral ordering between dark and bright excitons in transition metal dichalcogenides is of increasing interest for optoelectronic applications. However, little is known about dark exciton energies and their binding energies. We report the…
Excitons, namely neutral excitations in a system of electrons arising from the electron-hole interaction, are often essential to explain optical measurements in materials. They are governed by the Bethe-Salpeter equation, which can be cast…
The collective properties of different quasiparticles in various graphene based structures in high magnetic field have been studied. We predict Bose-Einstein condensation (BEC) and superfluidity of 2D spatially indirect magnetoexcitons in…