Related papers: Excitonic versus electron-hole liquid phases in Tm…
When electron-hole pairs are excited in a semiconductor, it is a priori not clear if they form a fermionic plasma of unbound particles or a bosonic exciton gas. Usually, the exciton phase is associated with low temperatures. In atomically…
The region surrounding the excitonic insulator phase is a three-component plasma composed of electrons, holes, and excitons. Due to the extended nature of the excitons, their presence influences the surrounding electrons and holes. We…
Excitons are promising candidates for generating superfluidity and Bose-Einstein Condensation (BEC) in solid state devices, but an enabling material platform with in-built bandstructure advantages and scaling compatibility with industrial…
Excitonic insulators (EI) arise from the formation of bound electron-hole pairs (excitons) in semiconductors and provide a solid-state platform for quantum many-boson physics. Strong exciton-exciton repulsion is expected to stabilize…
An excitonic insulator phase is expected to arise from the spontaneous formation of electron-hole pairs (excitons) in semiconductors where the exciton binding energy exceeds the size of the electronic band gap. At low temperature, these…
The bound electron-hole pairs known as excitons govern the optical properties of insulating solids. While their behavior in equilibrium is well-understood theoretically, the nonequilibrium regime at high excitation densities-where phenomena…
Electron-hole bound pairs, or excitons, are common excitations in semiconductors. They can spontaneously form and ``condense'' into a new insulating ground state -- the so-called excitonic insulator -- when the energy of electron-hole…
In the 1960s speculations arose if a ground state exists in solid state materials with an electron and a hole bound to a pair with their spins added to integer values, i.e. excitons. Here we show that electrons and holes in TmSe0.45Te0.55…
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…
We study the occurrence of excitonic superfluidity in electron-hole bilayers at zero temperature. We not only identify the crossover in the phase diagram from the BCS limit of overlapping pairs to the BEC limit of non-overlapping…
Excitonic insulator is a coherent electronic phase that results from the formation of a macroscopic population of bound particle-hole pairs - excitons. With only a few candidate materials known, the collective excitonic behavior is…
We calculate the critical temperature below which an excitonic insulator exists at the pressure-induced semiconductor-semimetal transition. Our approach is based on an effective-mass model for valence and conduction band electrons…
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…
We act on the suggestion that an excitonic insulator state might separate---at very low temperatures---a semimetal from a semiconductor and ask for the nature of these transitions. Based on the analysis of electron-hole pairing in the…
Using Diffusion Monte Carlo simulations we have investigated the ground state of a symmetric electron-hole bilayer and determined its phase diagram at T=0. We find clear evidence of an excitonic condensate, whose stability however is…
Two-dimensional electron-hole gases in colloidal semiconductors have a wide variety of applications. Therefore, a proper physical understanding of these materials is of great importance. In this paper we present a detailed theoretical…
We investigate the ground state of a balanced electron-hole system in the quantum Hall regime using mean-field theory and obtain a rich phase diagram as a function of interlayer distance d and the filling factor within a layer. We identify…
Excitons are electron-hole (e-h) pair quasiparticles, which may form a Bose-Einstein condensate (BEC) and collapse into the phase coherent state at low temperature. However, because of ephemeral strength of pairing, a clear evidence for BEC…
Electrons and holes in a semiconductor form hydrogen-atom-like bound states, called excitons. At high electron-hole densities the attractive Coulomb force becomes screened and excitons can no longer exist. Bardeen-Cooper-Schrieffer theory…
We study the texture of the exciton condensate at low temperatures in an independently gated electron-hole bilayer system. A model Hamiltonian is solved in real space within a mean-field approximation. It is found that, with increased…