Spin excitations in a degenerate two-dimensional electron gas in a perpendicular quantizing magnetic field are discussed, namely, purely electronic spin magnetoexcitons. These are spin-wave- and 'Goldstone' excitons in quantum Hall ferromagnetic (filling factor ν=1) — and spin-cyclotron excitons in quantum Hall isolator (ν=2). The latter ones are distinguished by record-breaking long lifetimes, up to 1 ms, which allows to observe the transition to a fundamentally new collective state — magnetofermionic condensate at temperatures T .
Keywords: magnetoexcitons, quantum Hall isolator, quantum Hall ferromagnetic, collective excitations, magnetofermionic condensate PACS:71.35.Lk, 73.21.Fg, 78.67.De (all) DOI:10.3367/UFNe.2018.10.038463 Citation: Kulik L V, Gorbunov A V, Dickmann S M, Timofeev V B "Spin excitations in two-dimensional electron gas, their relaxation, methods of photoexcitation and detection, role of Coulomb correlations" Phys. Usp., accepted
Received: 15th, June 2018, revised: 11th, October 2018, accepted: 31st, October 2018