Variational and field-theoretical approach to exciton-exciton interactions and biexcitons in semiconductors
arXiv:2510.05242 · doi:10.1103/hmkm-jxzl
Abstract
Bound electron-hole pairs in semiconductors known as excitons are the subject of intense research due to their potential for optoelectronic devices and applications, especially in the realm of two-dimensional materials. While the properties of free excitons in these systems are well understood, a general description of the interactions between these quasiparticles is complicated due to their composite nature, which leads to important exchange processes that can take place between the identical fermions of different excitons. In this work, we employ a variational approach to study interactions between Wannier excitons and obtain an effective interaction potential between two ground-state excitons in a system of spin-degenerate electrons and holes. This potential is in general nonlocal in position space and depends on the combined spin configurations of the electrons and holes. When particularized to the case of hydrogen-like excitons with a heavy hole, this potential becomes local and exactly reproduces the Heitler-London result for two interacting hydrogen atoms. Thus, our result can be interpreted as a generalization of the Heitler-London potential to the case of arbitrary masses. We also show how including corrections due to excited states into the theory results in a van der Waals potential at large distances, which is expected due to the induced dipole-dipole nature of the interactions. Our approach is also applicable to more complicated systems with nonhydrogenic exciton series, such as layered semiconductors with Rytova-Keldysh interactions. Additionally, we use a path-integral formalism to develop a many-body theory for a dilute gas of excitons, resulting in an excitonic action that formally includes many-body interactions between excitons. While in this approach the field representing the excitons is exactly bosonic, we clarify how the internal exchange processes arise in...
Final published version
References in corpus (24)
- Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
- Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
- Exciton band structure of monolayer MoS2
- Measurement of high exciton binding energy in the monolayer transition-metal dichalcogenides WS2 and WSe2
- Strongly correlated excitonic insulator in atomic double layers
- Nonlinear Photoluminescence in Atomically Thin Layered WSe2 Arising from Diffusion-Assisted Exciton-Exciton Annihilation
- Excitons versus electron-hole plasma in monolayer transition metal dichalcogenide semiconductors
- Analysis of the exciton-exciton interaction in semiconductor quantum wells
- Exciton-exciton interaction in transition-metal dichalcogenide monolayers
- Electron-exciton interactions in the exciton-polaron problem
- Collective Excitations in 2D Materials
- Exciton-exciton scattering: Composite boson versus elementary boson
- Towards superfluidity of dipolar excitons in a TMDC double layer
- Observation of exciton-exciton interaction mediated valley depolarization in monolayer MoSe
- Moiré-Bose-Hubbard model for interlayer excitons in twisted transition metal dichalcogenide heterostructures
- Observation of Chiral Surface Excitons in a Topological Insulator BiSe
- Coherent exciton-exciton interactions and exciton dynamics in a MoSe\textsubscript{2}/WSe\textsubscript{2} heterostructure
- Exciton-exciton interactions in van der Waals heterobilayers
- Observation of room temperature excitons in an atomically thin topological insulator
- Direct Measurement of Biexcitons in Monolayer WS2
- Terahertz parametric amplification as a reporter of exciton condensate dynamics
- Completeness of the Coulomb scattering wave functions
- Many-body perturbation theory for moiré systems
- Unconventional excitonic insulators in two-dimensional topological materials