Electron g factor in a gated InGaAs channel with double InAs-inserted wells

Lin, Yongbiao; Nitta, J.; Koga, Tomohiro; Akazaki, Tatsushi

doi:10.1016/j.physe.2003.11.098

Cited by 11 publications

(13 citation statements)

References 14 publications

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“…Although the sign of g * cannot be determined from our measurements, the fact that bulk InAs has a large and negative g factor while bulk AlAs has a small positive g factor indicates that g * is negative. 15,16 The electron effective g factor as a function of w at room temperature is plotted in Fig. 4͑a͒, showing that g * increases with increasing w consistent with the expected trends.…”

supporting

confidence: 73%

“…The data are fitted by adjusting the parameters 0 , T 2 * , and g * . The lack of additional frequency components and the agreement of g * with the expected value 15,16 for electrons indicate that hole spin precession is not observable.…”

mentioning

confidence: 72%

“…4͑a͒, showing that g * increases with increasing w consistent with the expected trends. 15,16 The electron spin coherence time T 2 * as a function of w at room temperature with applied magnetic field B = 0.6 T is displayed in Fig. 4͑b͒.…”

mentioning

confidence: 99%

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Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells

Lau

Sih

Stern

et al. 2006

Applied Physics Letters

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Articles you may be interested inElectronic band structures and electron spins of InAs/GaAs quantum dots induced by wetting-layer fluctuation J. Appl. Phys. 110, 054320 (2011); 10.1063/1.3633508 Effect of electron spin-spin exchange interaction on spin precession in coupled quantum well Room temperature gate modulation of electron spin relaxation time in (110)-oriented GaAs/AlGaAs quantum wells Appl. Phys. Lett. 97, 202102 (2010); 10.1063/1.3514675 Temperature dependence of the resistively detected electron spin resonance signals in a wide parabolic quantum well AIP Conf. Proc. 893, 633 (2007); 10.1063/1.2730050Room-temperature electric-field controlled spin dynamics in (110) InAs quantum wells

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confidence: 73%

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confidence: 72%

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Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells

Lau

Sih

Stern

et al. 2006

Applied Physics Letters

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“…Electrical control of isolated spins through their g-factors is highly desireable for implementation of quantum gate operations. To date, electrical control of g-factors has only been observed in ensembles of electrons in quantum wells by shifting the electron wavefunctions into different materials [10,11,12,13]. In this Letter we present a striking electric field resonance in the g-factor for molecular spin states confined to a single quantum dot molecule.…”

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confidence: 86%

Electrically TunablegFactors in Quantum Dot Molecular Spin States

et al. 2006

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We present a magneto-photoluminescence study of individual vertically stacked InAs/GaAs quantum dot pairs separated by thin tunnel barriers. As an applied electric field tunes the relative energies of the two dots, we observe a strong resonant increase or decrease in the g-factors of different spin states that have molecular wavefunctions distributed over both quantum dots. We propose a phenomenological model for the change in g-factor based on resonant changes in the amplitude of the wavefunction in the barrier due to the formation of bonding and antibonding orbitals. PACS numbers: 75.40.Gb, 78.20.Ls, 78.47.+p, 78.67.Hc Quantum Dots and Quantum Dot Molecules (QDMs) have proven to be a versatile medium for isolating and manipulating spins [1,2], which are of great interest for quantum information processing [3,4]. In particular, photoluminescence (PL) spectra have been used in self-assembled QDMs to observe coherent tunneling [5,6,7,8] and identify spin interactions through fine structure [9]. Electrical control of isolated spins through their g-factors is highly desireable for implementation of quantum gate operations. To date, electrical control of g-factors has only been observed in ensembles of electrons in quantum wells by shifting the electron wavefunctions into different materials [10,11,12,13]. In this Letter we present a striking electric field resonance in the g-factor for molecular spin states confined to a single quantum dot molecule.To our knowledge this is the first observation of electrical control over the g-factor for a single confined spin. Moreover, the isolation of a single QDM allows us to spectrally resolve and identify individual molecular spin states that have different g-factor behaviors. In Fig. 1a we indicate molecular spin states of both the neutral exciton (X 0 , one electron recombining with one hole) and positive trion (X + , electron-hole recombination in the presence of an extra hole) at zero magnetic field. The different electric field dependences of the g-factors for these states is apparent in Fig. 1b, where the splitting of PL lines increases for some molecular spin states and decreases for others. This electric field dependence is nearly an order of magnitude larger than previously reported in quantum wells [10,11,12,13]. The effect arises from the formation of bonding and antibonding orbitals, which results in a change in the amplitude of the wavefunction in the barrier at resonance.Our QDMs consist of two vertically stacked selfassembled InAs dots truncated at a thickness of 2.5 nm and separated by a 2 nm GaAs tunneling barrier [14]. As an applied electric field tunes the relative energies of the two dots, strong tunnel coupling between the hole states creates the molecular spin states. Unlike samples with a thicker tunnel barrier [5], the states retain molecular character throughout the observed range of electric fields. We present data from a single molecule, but the universality of the behavior has been verified by detailed studies of 7 other molecules from the same ...

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“…It has been implemented in a single quantum well (QW) (e.g., GaAs/AlGaAs heterostructure 6 or Al x Ga 1−x As QW with x gradually varying across the structure 7 ) and a coupled QW (e.g., two separate QWs made from AlAs and Al 0.1 Ga 0.9 As 8 ), a pair of undoped GaAs QWs with an Al 0.33 Ga 0.67 As barrier, 9 and InGaAs/InAlAs heterostructure with double InAs-inserted QWs. 10 The same scheme has also been applied to a coupled quantum dots system (e.g., vertically stacked InAs/GaAs quantum dot pairs 11 ) and enabled the electrical control of the g factor for a single confined spin rather than that for an ensemble of carrier spins in QW. In addition, as alternative approaches, the orbital mechanism of spin control was experimentally demonstrated for InAs-based QWs 12,13 and the many-body correction of the exciton wave function in terms of the electric field in coupled QWs was suggested.…”

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confidence: 99%

Electrically driven singularity and control of carrier spin of a hybrid quantum well

2011

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We propose a hybrid quantum well structure comprising a compressively strained layer and tensile-strained layer and find that the major band character of the valence band maximum can be switched between the heavy hole of the compressively strained layer and the light hole of the tensile-strained layer by application of an electric field. Remarkably, in the switching resonant region, we find that the g factors of both heavy-hole and light-hole states become singular (i.e., there is discontinuous change between positive and negative extrema), which enables the extreme control of the hole spin of the hybrid quantum well by the electric field.

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Electron g factor in a gated InGaAs channel with double InAs-inserted wells

Cited by 11 publications

References 14 publications

Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells

Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells

Electrically TunablegFactors in Quantum Dot Molecular Spin States

Electrically driven singularity and control of carrier spin of a hybrid quantum well

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