Related papers: {\it Ab--initio} finite temperature excitons
Wavepacket transport across a nonlinear region is studied numerically at zero and finite temperatures. In contrary to the zero temperature case which demonstrates ballistic transport, finite temperature lattice vibrations suppresses the…
Ultracold atoms uniformly filling an optical lattice can be treated like an artificial crystal. An implementation including the atomic occupation of a single excited atomic state can be represented by a two-component Bose-Hubbard model. Its…
It is strong Coulomb effects in carbon nanotubes that lead to formation of the so-called "bright" and "dark" (forbidden one-photon optical transition) exciton states, and dramatically decrease the efficiency of one-photon light emission via…
We utilize the dark state in a {\Lambda}-type three-level system to cool an ensemble of 85Rb atoms in an optical lattice [Morigi et al., Phys. Rev. Lett. 85, 4458 (2000)]. The common suppression of the carrier transition of atoms with…
Bound electron-hole excitonic states are generally not expected to form with charges of negative effective mass. We identify such excitons in a single layer of the semiconductor WSe2, where they give rise to narrow-band upconverted…
Owing to their small binding energies, excitons in bulk semiconductors typically exhibit a sharp optical peak at low temperatures only. This limitation can be overcome by single-walled carbon nanotubes (SWCNTs) and other low-dimensional…
Exciton-phonon interactions play a fundamental role in phonon-assisted radiative recombination and exciton dynamics in solids. In this work, we present a first-principles framework for computing phonon-assisted radiative lifetimes and…
Optical spectroscopy of ultimately thin materials has significantly enhanced our understanding of collective excitations in low-dimensional semiconductors. This is particularly reflected by the rich physics of excitons in atomically thin…
Laser melting of semiconductors has been observed for almost 40 years; surprisingly, it is not well understood where most theoretical simulations show a laser-induced thermal process. $\textit{Ab initio}$ nonadiabatic simulations based on…
We study the coupling of internal electronic excitations to vibrational modes of the external motion of ultracold atoms in an optical lattice. For different ground and excited state potentials the on-site coupling of excitations and…
Microcavity exciton-polaritons, known to exhibit non-equilibrium Bose condensation at high critical temperatures, can be also brought in thermal equilibrium with the surrounding medium and form a quantum degenerate Bose-Einstein…
We calculate the radiative lifetime and energy bandstructure of excitons in semiconducting carbon nanotubes, within a tight-binding approach. In the limit of rapid interband thermalization, the radiative decay rate is maximized at…
We propose a method for measuring the temperature of fermionic atoms in an optical lattice potential from the intensity of the scattered light in the far-field diffraction pattern. We consider a single-component gas in a tightly-confined…
We investigate strongly asymmetric self-assembled nanostructures with one of dimensions reaching hundreds of nanometers. Close to the nanowire-like type of confinement, such objects are sometimes assigned as one-dimensional in nature. Here,…
The high thermal conductivity of boron arsenide (BAs) makes it a promising material for optoelectronic applications in which thermal management is central. In this work, we study the finite temperature optoelectronic properties of BAs by…
The optical excitation spectra and excitonic resonances are investigated in systematically functionalized SiC with Fluorine and/or Chlorine utilizing density functional theory in combination with many-body perturbation theory. The latter is…
The response of cold atom gases to small periodic phase modulation of an optical lattice is discussed. For bosonic gases, the energy absorption rate is given, within linear response theory, by imaginary part of the current correlation…
We have computed finite temperature corrections to the electron-hadron scattering cross sections. These are based upon the renormalized electron mass and the modified density of states due to the presence of a background thermal bath. It is…
We present an exact study of the finite-temperature properties of hard-core bosons (HCB's) confined on one-dimensional optical lattices. Our solution of the HCB problem is based on the Jordan-Wigner transformation and properties of Slater…
To fully explore exciton-based applications and improve their performance, it is essential to understand the exciton behavior in anisotropic materials. Here, we investigate the optical properties of anisotropic excitons in GeS encapsulated…