Shun Takahashi

Electrically tuned spin-orbit interaction in an InAs self-assembled quantum dot

Electrical control over electron spin is a prerequisite for spintronics spin-based quantum information processing. In particular, control over the interaction between the orbital motion and the spin state of electrons would be valuable, because this interaction influences spin relaxation and dephasing. Electric fields have been used to tune the strength of the spin-orbit interaction in two-dimensional electron gases, but not, so far, in quantum dots. Here, we demonstrate that electrical gating can be used to vary the energy of the spin-orbit interaction in the range 50-150 µeV while maintaining the electron occupation of a single self-assembled InAs quantum dot. We determine the spin-orbit interaction energy by observing the splitting of Kondo effect features at high magnetic fields.

Large anisotropy of the spin-orbit interaction in a single InAs self-assembled quantum dot.

The anisotropy of the spin-orbit interaction (SOI) is studied for a single uncapped InAs self-assembled quantum dot holding just a few electrons. The SOI energy is evaluated from anticrossing or SOI-induced hybridization between the ground and excited states with opposite spins. The magnetic angular dependence of the SOI energy falls on an absolute cosine function for azimuthal rotation, and a cosinelike function for tilting rotation. Furthermore, the SOI energy is quenched for a specific magnetic field vector. The angular dependence of SOI is found to compare well with calculation of Rashba SOI in a two-dimensional harmonic potential.

Electrically tunable three-dimensionalg-factor anisotropy in single InAs self-assembled quantum dots

Three-dimensional anisotropy of the Lande

Circularly polarized vacuum field in three-dimensional chiral photonic crystals probed by quantum dot emission

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Quantitative evaluation of spin-orbit interaction in InAs quantum dots

factor and its electrical modulation are studied for single uncapped InAs self-assembled quantum dots (QDs). The

High-gain and wide-band optical amplifications induced by a coupled excited state of organic dye molecules co-doped in polymer waveguide

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Quantitative evaluation of light–matter interaction parameters in organic single-crystal microcavities

factor is evaluated from measurement of inelastic cotunneling via Zeeman substates in the QD for various magnetic field directions. We find that the value and anisotropy of the

High-Q nanocavities in semiconductor-based three-dimensional photonic crystals

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Control of quantum dot light emission by chiral photonic crystal structures

factor depends on the type of orbital state which arises from the three-dimensional confinement anisotropy of the QD potential. Furthermore, the

Control of Light Polarization using Photonic and Phononic Crystals

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