Generation and detection of mode-locked spin coherence in (In,Ga)As/GaAs quantum dots by laser pulses of long duration

Abstract

Using optical pulses of variable duration up to 80 ps, we report on spin coherence initialization and its subsequent detection in n-type singly-charged quantum dots, subject to a transverse magnetic field, by pump-probe techniques. We demonstrate experimentally and theoretically that the spin coherence generation and readout efficiencies are determined by the ratio of laser pulse duration to spin precession period: An increasing magnetic field suppresses the spin coherence signals for a fixed duration of pump and/or probe pulses, and this suppression occurs for smaller fields the longer the pulse duration is. The reason for suppression is the varying spin orientation due to precession during pulse action.

13 pages, 12 figures

References in corpus (7)

• Stimulated and spontaneous optical generation of electron spin coherence in charged GaAs quantum dots
• Optical control of spin coherence in singly charged (In,Ga)As/GaAs quantum dots
• Optical Read-Out and Initialization of an Electron Spin in a Single Quantum Dot
• Pump-Probe Faraday Rotation and Ellipticity in an Ensemble of Singly Charged Quantum Dots
• Spin coherence of a two-dimensional electron gas induced by resonant excitation of trions and excitons in CdTe/(Cd,Mg)Te quantum wells
• Robust manipulation of electron spin coherence in an ensemble of singly charged quantum dots
• Effect of pump-probe detuning on the Faraday rotation and ellipticity signals of mode-locked spins in InGaAs quantum dots

Cited by in corpus (8)

• Coherent spin dynamics of electrons and excitons in nanostructures
• Coherent spin dynamics of electrons and holes in semiconductor quantum wells and quantum dots under periodical optical excitation: resonant spin amplification versus spin mode-locking
• Quantum model for mode locking in pulsed semiconductor quantum dots
• Influence of the nuclear Zeeman effect on mode locking in pulsed semiconductor quantum dots
• Theory of optical spin control in quantum dot microcavities
• Resonant optical control of the electrically-induced spin polarization by periodic excitation
• Interplay of spin mode locking and nuclei-induced frequency focusing in quantum dots
• Nuclear magnetic resonance spectroscopy of nonequilibrium steady states in quantum dots