The ordered state and the elementary excitations are theoretically studied in an interacting dilute quasi-two-dimensional Bose gas of excitons in a type-II quantum well. This system is advantageous for studying the macroscopic quantum phenomena because those excitons have a long lifetime of the order of 10-6 s, and their transport mechanism can be directly studied in experiments by observing electric current since the excitons consist of spatially separated electron-hole pairs. Using the obtained dispersion relations for excitations, we examine the Landau criterion for exciton superflow and the temperature dependence of the off-diagonal long-range order which characterizes the quasi-Bose-Einstein condensation in two-dimensional systems.The ordered state and the elementary excitations are theoretically studied in an interacting dilute quasi-two-dimensional Bose gas of excitons in a type-II quantum well. This system is advantageous for studying the macroscopic quantum phenomena because those excitons have a long lifetime of the order of 10-6 s, and their transport mechanism can be directly studied in experiments by observing electric current since the excitons consist of spatially separated electron-hole pairs. Using the obtained dispersion relations for excitations, we examine the Landau criterion for exciton superflow and the temperature dependence of the off-diagonal long-range order which characterizes the quasi-Bose-Einstein condensation in two-dimensional systems.

International Journal of Modern Physics BDec 10, 20011 citation

Coherent excitations of excitons in a semiconductor

G. P. Golubev, V. Dneprovskij, E. V. Zimenko +2 more

Bulletin of the Russian Academy of Sciences PhysicsJun 1, 19810 citations

Mott transition in excitonic Bose polarons

E. A. Szwed, Brian Vermilyea, D. J. Choksy +5 more

For a neutral system of positive and negative charges, such as atoms in a crystal, increasing the density causes the Mott transition from bound electrons to free electrons. The density of optically generated electron-hole systems can be controlled in situ by the power of optical excitation that enables the Mott transition from excitons, the bound pairs of electrons and holes, to free electrons and holes with increasing density. These Mott transitions occur in systems of pairs of the same kind, such as atoms or excitons. However, a different type of the Mott transition can occur for Bose polarons. A Bose polaron is a mobile particle of one kind in a Bose gas of particles of another kind. For the Mott transition in polarons, the polaron states vanish with increasing density of the surrounding gas. In this paper, we present the observation of this type of the Mott transition and the measurement of the Mott transition parameter $n_{\rm M}^{1/2} a_{\rm B}$ in 2D excitonic Bose polarons.For a neutral system of positive and negative charges, such as atoms in a crystal, increasing the density causes the Mott transition from bound electrons to free electrons. The density of optically generated electron-hole systems can be controlled in situ by the power of optical excitation that enables the Mott transition from excitons, the bound pairs of electrons and holes, to free electrons and holes with increasing density. These Mott transitions occur in systems of pairs of the same kind, such as atoms or excitons. However, a different type of the Mott transition can occur for Bose polarons. A Bose polaron is a mobile particle of one kind in a Bose gas of particles of another kind. For the Mott transition in polarons, the polaron states vanish with increasing density of the surrounding gas. In this paper, we present the observation of this type of the Mott transition and the measurement of the Mott transition parameter $n_{\rm M}^{1/2} a_{\rm B}$ in 2D excitonic Bose polarons.

arXiv:2504.07227Apr 9, 20250 citations

Excited States and Collective Excitations in a Dense Gas of Excitons

Günter Manzke, Volkhard May, K. Henneberger

Abstract Following the concept of Hanamura the Bose formalism of Usui is used to investigate the collective properties of a dense gas of excitons. The correlation self‐energy for excitons is calculated with the help of a special concept of pure excitonic screening. The dielectric function and the collective modes are studied in detail. It is shown, that the consideration of excited exciton states leads to a lowering of the 1s exciton level with increasing exciton density. Furthermore the damping of the 1s exciton due to exciton–exciton collisions is investigated.Abstract Following the concept of Hanamura the Bose formalism of Usui is used to investigate the collective properties of a dense gas of excitons. The correlation self‐energy for excitons is calculated with the help of a special concept of pure excitonic screening. The dielectric function and the collective modes are studied in detail. It is shown, that the consideration of excited exciton states leads to a lowering of the 1s exciton level with increasing exciton density. Furthermore the damping of the 1s exciton due to exciton–exciton collisions is investigated.

physica status solidi (b)Oct 1, 198415 citations

Cooling of interacting-exciton gas

R. Baltramiejūnas, ARTŪRAS ŽUKAUSKAS, Gintautas Tamulaitis

Jul 1, 19857 citations

n_{\rm M}^{1/2} a_{\rm B}

in 2D excitonic Bose polarons.