Enhanced spin lifetimes in a two dimensional electron gas in a gate-controlled GaAs quantum well

Abstract

Exciton, trion and electron spin dynamics in a 20 nm wide modulation-doped GaAs single quantum well are investigated using resonant ultrafast two-color Kerr rotation spectroscopy. Excitons and trions are selectively detected by resonant probe pulses while their relative spectral weight is controlled by adjusting the gate voltage which tunes the carrier density. Tuning the carrier density markedly influences the spin decay time of the two dimensional electron gas. The spin decay time can be enhanced by a factor of 3 at an intermediate carrier concentration in the quantum well, where excitons and trions coexist in the system. In addition, we explore the capability to tune the g-factor of the electron gas via the carrier density.

arXiv comment6 pages, 5 figures

References in corpus (5)

• Optical pumping of electronic and nuclear spin in single charge-tunable quantum dots
• Stimulated and spontaneous optical generation of electron spin coherence in charged GaAs quantum dots
• Trion Formation Dynamics in Monolayer Transition Metal Dichalcogenides
• Coherent Electronic Coupling in Atomically Thin MoSe2
• The onset of exciton absorption in modulation doped GaAs quantum wells

Cited by in corpus (5)

• Long-Lived Valley Polarization of Intra-Valley Trions in Monolayer WSe2
• Persistent Spin Helix Manipulation by Optical Doping of a CdTe Quantum Well
• Valley Degree of Freedom in Two-Dimensional van der Waals Materials
• Gate-Control of Anisotropic Spin Transport and Spin Helix Dynamics in a Modulation-Doped GaAs Quantum Well
• Spin helices in GaAs quantum wells: Interplay of electron density, spin diffusion, and spin lifetime