Radiative Decay of Bound Electron Pairs in Two-Dimensional Topological Insulators

Abstract

Bound electron pairs (BEPs) with energy in the band gap are interesting because they can participate in charge and spin transport in modern topologically nontrivial materials. We address the problem of their stability and study the radiative decay of the BEPs formed due to the negative reduced effective mass in two-dimensional topological insulators. The decay time is found to be rather large on the scale of the characteristic relaxation times of the electron system and significantly dependent on the topological properties and dispersion of the band states. In topological phase the decay time is much longer than in the trivial one, and is estimated as $\sim$1~ns for the HgTe/CdHgTe heterostructures. However, the longest decay time is in the topological phase with nearly flat dispersion in the band extema.

5 pages, 4 figures. Accepted in Physica Status Solidi RRL

References in corpus (7)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Excitons in atomically thin transition metal dichalcogenides
• Repulsively bound atom pairs in an optical lattice
• Spin-orbit-driven electron pairing in two dimensions
• Two-body problem for two-dimensional electrons in Bernervig-Hughes-Zhang model
• Zero-energy vortices in Dirac materials
• Doublon lifetimes in dissipative environments

Cited by in corpus (3)

• Electron pairs bound by the spin-orbit interaction in 2D gated Rashba materials with two-band spectrum
• Effective Mass of Bound Electron Pairs in Two-Dimensional Materials with a Gapped Band Spectrum
• Radiative decay of bound electron pairs into unbound interacting electrons in 2D materials with two-band spectrum