Voltage Control of the Spin Dynamics of an Exciton in a Semiconductor Quantum Dot

Smith, Jason M.; Dalgarno, Paul A.; Warburton, Richard J.; Govorov, Alexander O.; Karraï, K.; Gerardot, Brian D.; Petroff, P. M.

doi:10.1103/physrevlett.94.197402

Cited by 164 publications

(153 citation statements)

References 11 publications

Supporting

Mentioning

139

Contrasting

Order By: Relevance

“…We then set the gate voltage to where the co-tunneling induced spin flip process is suppressed [19]. Figure 2(a) shows a single beam absorption spectrum by scanning the laser across transition H1 at a magnetic field of .…”

mentioning

confidence: 99%

Coherent population trapping of an electron spin in a single negatively charged quantum dot

et al. 2008

View full text Add to dashboard Cite

mentioning

confidence: 99%

Coherent population trapping of an electron spin in a single negatively charged quantum dot

et al. 2008

View full text Add to dashboard Cite

“…This is an upper bound for the corresponding DNSP decay rate which will be slowed by additional effects like the inhomogeneous Knight field the nuclei are exposed to. Secondly, the spin of the residual electron is randomized due to co-tunnelling to the close-by electron reservoir on a timescale of τ el ∼ 20 ns [17]. This electron spin depolarization is then mapped onto the nuclear spin system via hyperfine flip-flop events.…”

mentioning

confidence: 99%

Dynamics of Quantum Dot Nuclear Spin Polarization Controlled by a Single Electron

2007

View full text Add to dashboard Cite

We present an experimental study of the dynamics underlying the buildup and decay of dynamical nuclear spin polarization in a single semiconductor quantum dot. Our experiment shows that the nuclei can be polarized on a time scale of a few milliseconds, while their decay dynamics depends drastically on external parameters. We show that a single electron can very efficiently depolarize the nuclear spins and discuss two processes that can cause this depolarization. Conversely, in the absence of a quantum dot electron, the lifetime of nuclear spin polarization is on the time scale of a second, most likely limited by the non-secular terms of the nuclear dipole-dipole interaction. We can further suppress this depolarization rate by 1 − 2 orders of magnitude by applying an external magnetic field exceeding 1 mT.PACS numbers: 73.21. La, 78.67.Hc, 71.35.Pq, 71.70.Jp, 72.25.Fe, 72.25.Rb Optically active, self assembled single quantum dots (QDs) present an excellent system for studying optically induced dynamical nuclear spin polarization (DNSP) on an isolated ensemble of ∼ 10 4−5 nuclear spins. While the dynamics of DNSP of nuclei close to paramagnetic impurities in bulk semiconductors has already been studied [1], addressing a single, isolated island of spin polarized nuclei has not been possible up to now. Studying the dynamics of DNSP in a single QD has the advantage of removing effects of sample inhomogeneities and crosstalk between the individual islands of spin polarized nuclei. Also, the different atomic composition and strain distribution of the QD compared to its surrounding host material further decouples the QD nuclear spins from their environment. These facts distinguish the coupled QD electron-nuclear spin system as a well isolated system of a single electron spin, coupled to a slowly varying, small nuclear spin reservoir. A further interesting aspect of this system is its similarity to the Jaynes-Cummings model in quantum optics [2], with the fully polarized nuclear spin state corresponding to the cavity vacuum state. Controlling and understanding this system to a higher degree might lead to interesting experiments such as the coherent exchange of information between the electron and the nuclear spin reservoir [3,4].Optical orientation of QD nuclear spins has experimentally been demonstrated by a few groups [5,6,7,8,9]. However, the degree of DNSP achieved in these experiments has been limited to ∼ 10 − 20 percent. A detailed analysis of the formation as well as of the limiting factors of DNSP is thus required and might open ways to reach higher degrees of DNSP. A key ingredient for this understanding is the knowledge of the relevant timescales of the dynamics of nuclear spin polarization. Many questions like the respective roles of nuclear spin diffusion, quadrupolar relaxation and trapped excess QD charges on the depolarization of the nuclear spin system remain open up to now. While the buildup time of DNSP (τ buildup ) is likely to be dependant on the way the nuclear spin system is addressed, the DNSP ...

show abstract

“…12 In our device a n-type back contact is separated from annealed InGaAs/ GaAs dots by a 25 nm GaAs barrier. A capping layer of either 30 nm ͑sample A͒ or 10 nm ͑sample B͒ separates the dots from an AlAs/ GaAs blocking barrier ͑Fig.…”

mentioning

confidence: 99%

“…A dc bias between a NiCr Schottky gate on the device surface and the back contact allows for controlled tunneling of electrons into the dots on time scales of ϳ10 ps. 12 PL is detected using a low temperature microscope at 5 K. Excitation is provided by a nonresonant, 1.50 eV ͑826 nm͒, pulsed laser at 20 MHz with a measured full width at half maximum of ϳ50 ps. Excitation power is adjusted through the use of optical attenuators in order to preserve the temporal properties of the laser.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Hole recapture limited single photon generation from a single n-type charge-tunable quantum dot

Dalgarno

McFarlane

Brunner

et al. 2008

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

Spin accumulation in parallel-coupled quantum dots driven by a symmetric dipolar spin battery J. Appl. Phys. 111, 053708 (2012) Enhancement of thermoelectric efficiency and violation of the Wiedemann-Franz law due to Fano effect J. Appl. Phys. 111, 053704 (2012) Tunable spin manipulation in a quantum dot embedded in an Aharonov-Bohm interferometer J. Appl. Phys. 111, 054306 (2012) Back-action-induced non-equilibrium effect in electron charge counting statistics Appl. Phys. Lett. 100, 092112 (2012) Modulating quantum transport by transient chaos Appl. Phys. Lett. 100, 093105 (2012) Additional information on Appl. Phys. Lett.

show abstract

Voltage Control of the Spin Dynamics of an Exciton in a Semiconductor Quantum Dot

Cited by 164 publications

References 11 publications

Coherent population trapping of an electron spin in a single negatively charged quantum dot

Coherent population trapping of an electron spin in a single negatively charged quantum dot

Dynamics of Quantum Dot Nuclear Spin Polarization Controlled by a Single Electron

Hole recapture limited single photon generation from a single n-type charge-tunable quantum dot

Contact Info

Product

Resources

About