Coherent Spin Dynamics of Carriers

Yakovlev, D. R.; Bayer, Manfred

doi:10.1007/978-3-319-65436-2_6

Cited by 23 publications

(36 citation statements)

References 110 publications

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“…As a result of this spin mode locking (ML), the revival of the spin polarization occurs just before the arrival of the next laser pulse. Furthermore, periodic pumping results in a polarization of nuclear spins bringing a majority of QDs in a ML condition through the hyperfine interaction known as the nuclei-induced frequency focusing (NIFF) effect [12,13].…”

Section: Introductionmentioning

confidence: 99%

Decay and revival of electron spin polarization in an ensemble of (In,Ga)As quantum dots

et al. 2018

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The periodic optical orientation of electron spins in (In,Ga)As/GaAs quantum dots leads to the formation of electron spin precession modes about an external magnetic field which are resonant with the pumping periodicity. As the electron spin is localized within a nuclear spin bath, its polarization imprints onto the spin polarization of the bath. The latter acts back on the electron spin polarization. We implement a pulse protocol where a train of laser pulses is followed by a long, dark gap. It allows us to obtain a high-resolution precession mode spectrum from the free evolution of the electron spin polarization. Additionally, we vary the number of pump pulses in a train to investigate the build-up of the precession modes. To separate out nuclear effects, we suppress the nuclear polarization by using a radio-frequency field. We find that a long-living nuclear spin polarization imprinted by the periodic excitation significantly speeds up the buildup of the electron spin polarization and induces the formation of additional electron spin precession modes. To interpret these findings, we extend an established dynamical nuclear polarization model to take into account optically detuned quantum dots for which nuclear spins activate additional electron spin precession modes.

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Section: Introductionmentioning

confidence: 99%

Decay and revival of electron spin polarization in an ensemble of (In,Ga)As quantum dots

et al. 2018

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“…In this respect the suggested model has some analogy with the model describing the generation of spin coherence in low-density electron or hole gases via resonant excitation of trion states in QWs [18,20]. At zero magnetic field the magnetic moments of the HMPs, M MP , are equally distributed between the orientations parallel and antiparallel to the z axis so that the total polarization of the HMP ensemble is zero, see Fig.…”

Section: Model Of Optical Orientation Of Hole Magnetic Polaronmentioning

confidence: 93%

“…The recombination times τ of the QW exciton and trion in both structures are in the range of 100 ps and do not exceed 130 ps at T = 1.8 K (see Figs. 1(b) and 1(c)), which is typical for CdTe and (Cd,Mn)Te based QWs [17,18]. Despite the presence of the magnetic Mn ions, the dynamic spectral shift of the PL lines to low Time-resolved pump-probe Kerr rotation (KR) was used to study the spin dynamics in these structures [8,20].…”

Section: Experimentalsmentioning

confidence: 99%

Optical orientation of hole magnetic polarons in (Cd,Mn)Te/(Cd,Mn,Mg)Te quantum wells

et al. 2016

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The optically induced spin polarization in (Cd,Mn)Te/(Cd,Mn,Mg)Te diluted-magneticsemiconductor quantum wells is investigated by means of picosecond pump-probe Kerr rotation. At 1.8 K temperature, additionally to the oscillatory signals from photoexcited electrons and Manganese spins precessing about an external magnetic field, a surprisingly long-lived (up to 60 ns) nonoscillating spin polarization is detected. This polarization is related to optical orientation of equilibrium magnetic polarons involving resident holes. The suggested mechanism for the optical orientation of the equilibrium magnetic polarons indicates that the detected polaron dynamics originates from unexcited magnetic polarons. The polaron spin dynamics is controlled by the anisotropic spin structure of the heavy-hole resulting in a freezing of the polaron magnetic moment in one of the two stable states oriented along the structure growth axis. Spin relaxation between these states is prohibited by a potential barrier, which depends on temperature and magnetic field. The magnetic polaron relaxation is accelerated with increasing temperature and in magnetic field.

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“…In this paper we address the spin lifetimes of carriers in InAs/In 0.53 Al 0.24 Ga 0. 23 As/InP QDs emitting at telecom wavelengths which have not been measured so far to the best of our knowledge. At weak magnetic fields, the spin dynamics of the resident electrons in the QDs is governed by the hyperfine interaction with the nuclei and the regime described theoretically in Ref.…”

Section: Introductionmentioning

confidence: 89%

“…The dephasing time T * 2 of each of the carrier spin polarizations at low temperatures is determined by the random nuclear Overhauser fields B N (which act on the carrier spins via the hyperfine interaction) if the external magnetic field B V is smaller than B N . At higher B V , on the other hand, the time T * 2 is determined by the spread of the g-factors δg in the QD ensemble [23]:…”

Section: Methodsmentioning

confidence: 99%

Electron and hole spin relaxation in InP-based self-assembled quantum dots emitting at telecom wavelengths

et al. 2018

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We investigate the electron and hole spin relaxation in an ensemble of self-assembled InAs/In0.53Al0.24Ga0.23As/InP quantum dots with emission wavelengths around 1.5 µm by pumpprobe Faraday rotation spectroscopy. Electron spin dephasing due to the randomly oriented nuclear Overhauser fields is observed. At low temperatures we find a sub-microsecond longitudinal electron spin relaxation time T1 which unexpectedly strongly depends on temperature. At high temperatures the electron spin relaxation time is limited by optical phonon scattering through spin-orbit interaction decreasing down to 0.1 ns at 260 K. We show that the hole spin relaxation is activated much more effectively by a temperature increase compared to the electrons.

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Coherent Spin Dynamics of Carriers

Cited by 23 publications

References 110 publications

Decay and revival of electron spin polarization in an ensemble of (In,Ga)As quantum dots

Decay and revival of electron spin polarization in an ensemble of (In,Ga)As quantum dots

Optical orientation of hole magnetic polarons in (Cd,Mn)Te/(Cd,Mn,Mg)Te quantum wells

Electron and hole spin relaxation in InP-based self-assembled quantum dots emitting at telecom wavelengths

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