Related papers: Phase coherence and spectral functions in the two-…
Photoinduced dynamics in an excitonic insulator is studied theoretically by using a two-orbital Hubbard model on the square lattice where the excitonic phase in the ground state is characterized by the BCS-BEC crossover as a function of the…
We study the nonequilibrium dynamics in the pump-probe spectroscopy of excitonic insulators using the spinless two-orbital model with phonon degrees of freedom in the time-dependent mean-field approximation. We introduce the pulse light as…
We study the interactions between two atomic species in a binary Bose-Einstein condensate to revisit the conditions for miscibility, oscillatory dynamics between the species, steady state solutions and their stability. By employing a…
We develop a general theory of a boson decomposition for both local and non-local interactions in lattice fermion models which allows us to describe fermionic degrees of freedom and collective charge and spin excitations on equal footing.…
Excitonic insulators (EIs), arising in semiconductors when the electron-hole binding energy exceeds the band gap, are a solid-state prototype for bosonic phases of matter. Unlike the charged excitations that are frozen and unable to…
Phase transformations induced by short optical pulses are mainstream in studies on the dynamics of cooperative electronic states. We present a semi-phenomenological modeling of spacio-temporal effects expected when optical excitons are…
In this work, we theoretically investigate the optical orientation and alignment of excitons in quantum dots with weak electron-hole exchange interaction and long exciton radiative lifetimes. This particular regime is realized in…
Using the axially-symmetric time-dependent Gross-Pitaevskii equation we study the phase coherence in a repulsive Bose-Einstein condensate (BEC) trapped by a harmonic and an one-dimensional optical lattice potential to describe the…
We use Perturbative Continuous Unitary Transformations (PCUT) to study the one dimensional Extended Ionic Hubbard Model (EIHM) at half-filling in the band insulator region. The extended ionic Hubbard model, in addition to the usual ionic…
Excitonic insulators host the condensates of bound electron-hole pairs, offering a platform for studying correlated bosonic quantum states. Yet, how macroscopic coherence emerges from locally collapsed pairing remains elusive. Here, using…
We examine the possibility of Bose-Einstein condensation (BEC) in two-dimensional (2D) system of interacting particles in a trap. We use a self-consistent mean-field theory of Bose particles interacting by a contact interaction in the Popov…
We report quantum coherent oscillations of photocapacitance of a double-barrier resonant tunneling heterostructure with bias at 10 K. Periodic presence and absence of sharp excitonic transitions in photocapacitance spectra with increasing…
The excitonic insulator (EI) is an exotic ground state of narrow-gap semiconductors and semimetals arising from spontaneous condensation of electron-hole pairs bound by attractive Coulomb interaction. Despite research on EIs dating back to…
With the integral representation of Bose functions, the Bose-Einstein condensation of non-interacting bosons in a three-dimensional harmonic trap was studied. The relation between the particle number and its phase transition temperature was…
Excitons are compound particles formed from an electron and a hole in semiconductors. The impact of this substructure on the phonon-exciton interaction is described by a closed system of microscopic scattering equations. To calculate the…
We apply the topological theory of symmetry indicators to interaction-induced exciton band structures in centrosymmetric semiconductors. Crucially, we distinguish between the topological invariants inherited from the underlying electron and…
A new state of matter, an excitonic insulator (EI) state, was predicted to emerge from Bose-Einstein condensation of electron-hole pairs. Some candidate materials were suggested but it has been elusive to confirm its existence. Recent works…
Symmetric electron-hole bilayer systems have been studied at zero temperature using the diffusion quantum Monte Carlo method. A flexible trial wave function is used that can describe fluid, excitonic and biexcitonic phases. We calculate…
Under the Thomas-Fermi approximation, a relatively much simpler analytical solutions of the coupled Gross-Pitaevskii equations for the two-species BEC have been derived. Additionally, a model for the asymmetric states has been proposed, and…
We report on small-cluster exact-diagonalization calculations which prove the formation of electron-hole pairs (excitons) as prerequisite for spontaneous interlayer phase coherence in bilayer systems described by the extended…