A. S. Bracker

Fast spin rotations and optically controlled geometric phases in a quantum dot (2009)

Kim, Erik D., Truex, Katherine, Xu, Xiaodong, Sun, Bo, Steel, D. G., Bracker, A. S., ...

We demonstrate arbitrary rotations of an electron spin qubit in a charge-tunable InAs quantum dot using a combination of circularly polarized picosecond optical pulses and spin precession about a...

Hole Spin Mixing in InAs Quantum Dot Molecules (2009)

Doty, M. F., Climente, J. I., Greilich, A., Bracker, A. S., Gammon, D.

Holes confined in single InAs quantum dots have recently emerged as a promising system for the storage or manipulation of quantum information. These holes are often assumed to have only heavy-hole...

All-Optical Ultrafast Control and Read-Out of a Single Negatively Charged Self-Assembled InAs Quantum Dot (2009)

Kim, Erik D., Smirl, Katherine, Wu, Yanwen, Amo, A., Xu, Xiaodong, Steel, D. G., ...

We demonstrate the all-optical ultrafast manipulation and read-out of optical transitions in a single negatively charged self-assembled InAs quantum dot, an important step towards ultrafast control...

Electric field tunable exchange interaction in InAs/GaAs coupled quantum dots (2009)

Wijesundara, Kushal C., Garrido, Mauricio, Ramanathan, Swati, Stinaff, E. A., Scheibner, M., Bracker, A. S., ...

Spin manipulation in coupled quantum dots is of interest for quantum information applications. Control of the exchange interaction between electrons and holes via an applied electric field may...

Characterization of the Shell Structure in Coupled Quantum Dots through Resonant Optical Probing (2009)

Garrido, Mauricio, Wijesundara, Kushal C., Ramanathan, Swati, Stinaff, E. A., Scheibner, M., Bracker, A. S., ...

Excited states in single quantum dots (QDs) have been shown to be useful for spin state initialization and manipulation. For scalable quantum information processing it is necessary to have multiple...

Control of the direction and rate of nuclear spin flips in InAs quantum dots using detuned optical pulse trains (2009)

Carter, S. G., Shabaev, A., Economou, Sophia E., Kennedy, T. A., Bracker, A. S., Reinecke, T. L.

We find that detuning an optical pulse train from electronic transitions in quantum dots controls the direction of nuclear spin flips. The optical pulse train generates electron spins that precess...

Antibonding ground states in semiconductor artificial molecules (2008)

Doty, M. F., Climente, J. I., Korkusinski, M., Scheibner, M., Bracker, A. S., Hawrylak, P., ...

The spin-orbit interaction is a crucial element of many semiconductor spintronic technologies. Here we report the first experimental observation, by magneto-optical spectroscopy, of a remarkable...

A Single Charged Quantum Dot in a Strong Optical Field: Absorption, Gain, and the AC Stark Effect (2008)

Xu, Xiaodong, Sun, Bo, Kim, Erik D., Smirl, Katherine, Berman, P. R., Steel, D. G., ...

We investigate a singly-charged quantum dot under a strong optical driving field by probing the system with a weak optical field. When the driving field is detuned from the trion transition, the...

Stimulated Raman spin coherence and spin-flip induced hole burning in charged GaAs quantum dots (2007)

Cheng, Jun, Yao, Wang, Xu, Xiaodong, Steel, D. G., Bracker, A. S., Gammon, D., ...

High-resolution spectral hole burning (SHB) in coherent nondegenerate differential transmission spectroscopy discloses spin-trion dynamics in an ensemble of negatively charged quantum dots. In the...

Photoluminescence Spectroscopy of the Molecular Biexciton in Vertically Stacked Quantum Dot Pairs (2007)

Scheibner, M., Ponomarev, I. V., Stinaff, E. A., Doty, M. F., Bracker, A. S., Hellberg, C. S., ...

We present photoluminescence studies of the molecular neutral biexciton-exciton spectra of individual vertically stacked InAs/GaAs quantum dot pairs. We tune either the hole or the electron levels of...

Electrical control of optical orientation of neutral and negatively charged excitons in n-type semiconductor quantum well (2006)

Dzhioev, R. I., Korenev, V. L., Lazarev, M. V., Sapega, V. F., Gammon, D., Bracker, A. S.

We report a giant electric field induced increase of spin orientation of excitons in n-type GaAs/AlGaAs quantum well. It correlates strongly with the formation of negatively charged excitons (trions)...

Electrically tunable g-factors in quantum dot molecular spin states (2006)

Doty, M. F., Scheibner, M., Ponomarev, I. V., Stinaff, E. A., Bracker, A. S., Korenev, V. L., ...

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...

Spin Fine Structure in Optically Excited Quantum Dot Molecules (2006)

Scheibner, M., Doty, M. F., Ponomarev, I. V., Bracker, A. S., Stinaff, E. A., Korenev, V. L., ...

The interaction between spins in coupled quantum dots is revealed in distinct fine structure patterns in the measured optical spectra of InAs/GaAs double quantum dot molecules containing zero, one,...

Internal transitions of quasi-2D charged magneto-excitons in the presence of purposely introduced weak lateral potential energy variations (2006)

Meining, C. J., Whiteside, V. R., McCombe, B. D., Dzyubenko, A. B., Tischler, J. G., Bracker, A. S., ...

Optically detected resonance spectroscopy has been used to investigate effects of weak random lateral potential energy fluctuations on internal transitions of charged magneto-excitons (trions) in...

Polarized fine structure in the excitation spectrum of a negatively charged quantum dot (2005)

Ware, M. E., Stinaff, E. A., Gammon, D., Doty, M. F., Bracker, A. S., Gershoni, D., ...

We report polarized photoluminescence excitation spectroscopy of the negative trion in single charge tunable InAs/GaAs quantum dots. The spectrum exhibits a p-shell resonance with polarized fine...

Stimulated and spontaneous optical generation of electron spin coherence in charged GaAs quantum dots (2005)

Dutt, M. V. Gurudev, Cheng, Jun, Li, Bo, Xu, Xiaodong, Li, Xiaoqin, Berman, P. R., ...

We report on the coherent optical excitation of electron spin polarization in the ground state of charged GaAs quantum dots via an intermediate charged exciton (trion) state. Coherent optical fields...

Polarized fine structure in the photoluminescence excitation spectrum of a negatively charged quantum dot (2005)

Ware, M. E., Stinaff, E. A., Gammon, D., Doty, M. F., Bracker, A. S., Gershoni, D., ...

We report polarized photoluminescence excitation spectroscopy of the negative trion in single charge-tunable InAs/GaAs quantum dots. The spectrum exhibits a p-shell resonance with polarized fine...

Polarized fine structure in the photoluminescence excitation spectrum of a negatively charged quantum dot (2005)

Ware, M. E., Stinaff, E. A., Gammon, D., Doty, M. F., Bracker, A. S., Gershoni, D., ...

We report polarized photoluminescence excitation spectroscopy of the negative trion in single charge-tunable InAs/GaAs quantum dots. The spectrum exhibits a p-shell resonance with polarized fine...

Optical pumping of electronic and nuclear spin in single charge-tunable quantum dots (2004)

Bracker, A. S., Stinaff, E. A., Gammon, D., Ware, M. E., Tischler, J. G., Shabaev, A., ...

We present a comprehensive examination of optical pumping of spins in individual GaAs quantum dots as we change the charge from positive to neutral to negative using a Schottky diode. We observe that...

Suppression of Dyakonov-Perel Spin Relaxation in high mobility n-GaAs (2004)

Dzhioev, R. I., Kavokin, K. V., Korenev, V. L., Lazarev, M. V., Poletaev, N. K., Zakharchenya, B. P., ...

We report a large and unexpected suppression of the free electron spin relaxation in lightly-doped n-GaAs bulk crystals. The spin relaxation rate shows weak mobility dependence and saturates at a...

Magnetotunneling Between Two-dimensional Electron Gases in InAs-AlSb-GaSb Heterostructures (2003)

Lin, Y., González, E. M., Mendez, E. E., Magno, R., Bennett, B. R., Bracker, A. S.

We have observed that the tunneling magnetoconductance between two-dimensional (2D) electron gases formed at nominally identical InAs-AlSb interfaces most often exhibits two sets of Shubnikov-de Haas...

FTIR Studies of H2O and D2O Decomposition on Porous Silicon Surfaces. (1998)

Gupta, P., Dillon, A. C., Bracker, A. S., George, S. M.

The decomposition of H2O and D2O on silicon surfaces was studied using transmission Fourier-Transform Infrared (FTIR) spectroscopy. These FTIR studies were performed in-situ in an ultra-high vacuum...

Ammonia Decomposition on Silicon Surfaces Studied Using Transmission FTIR Spectroscopy. (1998)

Dillon, A. C., Gupta, P., Robinson, M. B., Bracker, A. S., George, S. M.

Fourier Transform Infrared (FTIR) transmission spectroscopy was used to monitor the decomposition of NH3 and ND3 on silicon surfaces. Experiments were performed in-situ in an ultra-high vacuum (UHV)...

FTIR Studies of Water and Ammonia Decomposition on Silicon Surfaces. (1998)

Dillon, A. C., Gupta, P., Robinson, M. B., Bracker, A. S., George, S. M.

Fourier transform infrared (FTIR) transmission spectroscopy was used to monitor the decomposition of H2O(D2O) and NH3 (ND3) on silicon surfaces. Experiments were performed in-situ in an ultra-high...

Fine Structure of Trious and Excitons in Single GaAs Quantum Dots (1998)

Tischler, J. G., Bracker, A. S., Gammon, D., Park, D.

Trions and excitons, localized laterally in quantum-dot-like potentials in GaAs quantum wells, were studied by magnetophotoluminescence spectroscopy as a function of magnetic field strength and...