Related papers: A minimal model for excitons within time-dependent…
Applying the novel exact-exchange (EXX) Kohn-Sham method within time-dependent density-functional theory, we obtained the optical absorption spectrum of bulk silicon in good agreement with experiments including excitonic features. Analysis…
We show how strongly correlated materials could be described within the framework of an excitonic insulator formalism, and delineate the relationship between inter- and intra-band ordering phenomena. Our microscopic model of excitons…
A system of several Wannier-Mott excitons interacting with phonons in a bulk material is considered. We show that strong exciton-phonon coupling causes the formation of a coherent two-exciton state -- the exciton pair. Unlike the…
Excitonic effects in the linear optical response of semiconductors are well-known and the subject of countless experimental and theoretical studies. For the technologically important second order nonlinear response, however, description of…
We assess a variant of linear-response range-separated time-dependent density-functional theory (TDDFT), combining a long-range Hartree-Fock (HF) exchange kernel with a short-range adiabatic exchange-correlation kernel in the local-density…
The magnetic field dependence of photoabsorption provides direct insights into the band structure of semiconductors. It is perhaps surprising that there is a large discrepancy between electron, hole, and reduced mass reported in the recent…
The real-time electronic dynamics on material surfaces is critically important to a variety of applications. However, their simulations have remained challenging for conventional methods such as the time-dependent density-functional theory…
Spectral density functions are central to the simulation of complex many body systems. Their determination requires to make approximations not only to the dynamics but also to the underlying electronic structure theory. Here, blending…
We construct a many-body model Hamiltonian to capture how phonons renormalize exciton binding as a function of temperature. By using the GW approximation and density functional perturbation theory, we are able to parameterize this…
The electron density $n(\rb,t)$, which is the central tool of time-dependent density functional theory, is presently considered to be derivable from a one-body time-dependent potential $V(\rb,t)$, via one-electron wave functions satisfying…
We demonstrated the potential of the fractional dimensional approach to understand exciton parameters in the exemplary atomically thin semiconductor material, a monolayer of WS$_2$. This approach has proved to be successful in finding the…
When transition-metal dichalcogenide monolayers lack inversion symmetry, their low-energy single particle spectrum can described by tilted massive Dirac Hamiltonians. The so-called Janus materials fall into that category. Inversion symmetry…
Motivated by the possibility of pressure-induced exciton condensation in intermediate-valence Tm[Se,Te] compounds we study the Falicov-Kimball model extended by a finite f-hole valence bandwidth. Calculating the Frenkel-type exciton…
The dynamics of a many-body system coupled to an external environment represents a fundamentally important problem. To this class of open quantum systems pertains the study of energy transport and dissipation, dephasing, quantum measurement…
Previous theoretical studies on superconductivity were focused on the static states and adiabatic processes. Quantum mechanics simulations of time-dependent processes in superconductors were rarely performed previously. Here we use…
Exciton dynamics dictate the evolution of photoexcited carriers in photovoltaic and optoelectronic devices. However, interpreting their experimental signatures is a challenging theoretical problem due to the presence of both electron-phonon…
The 2p-3d core hole interaction in the L2,3 absorption spectra of the 3d transition metals is treated within time-dependent density functional theory (TDDFT). A simple three-level model explains the origin of the strong deviations from the…
Exciton-exciton interactions are key to understanding non-linear optical and transport phenomena in van der Waals heterobilayers, which emerged as versatile platforms to study correlated electronic states. We present a combined…
We present a time-dependent density functional theory (TDDFT) based approach to compute the light-matter couplings between two different manifolds of excited states relative to a common ground state. These quantities are the necessary…
We derive a time-dependent density functional theory appropriate for calculating the near-edge X-ray absorption spectrum in molecules and condensed matter. The basic assumption is to increase the space of many-body wave functions from one…