Quantum Dots

Principal Investigators:

Dr. Daniel Gammon, dan.gammon@nrl.navy.mil

Dr. Allan S. Bracker, allan.bracker@nrl.navy.mil

We have an extensive research effort to explore and develop quantum dot materials for quantum information science and technology. This program encompasses MBE growth, fabrication, optical spectroscopy, and coherent optical control. The materials are based on self-assembled InAs quantum dots on GaAs. Nucleation techniques are used to grow ordered quantum dot molecules. The dots are embedded in Schottky diode heterostructures so that individual carriers can be injected and coherent tunneling of carriers between quantum dots can be controlled. Both electrons and holes are of interest for spin qubits in quantum dots. Photoluminescence spectroscopy is used to characterize the optical spectra, and direct absorption spectroscopy with continuous and pulsed lasers is used to carry quantum operations, such as spin initialization, spin-preserving measurement, and quantum gates on one or two spin qubits.

2011

• Optical control of one and two hole spins in interacting quantum dots, Nature Photonics, Vol 5 Issue 11, pp 703-709 (2011).

2010

• Three-Dimensional Control of Self-Assembled Quantum Dot Configurations, ACS NANO Vol. 4 Issue 7 pp 3877-3882 (2010).

2009

• Antibonding ground states in InAs quantum dot molecules, Phys. Rev. Lett. 102, 047401 (2009).

2008

• Optical spin spin initialization and nondestructive measurement in a quantum dot molecule, Phys. Rev. Lett. 101, 236804 (2008).
• Optically mapping the electronic structure of coupled quantum dots, Nature Physics 4, 291 (2008).

2007

• Photoluminescence spectroscopy of the molecular biexciton in vertically stacked InAs-GaAs quantum dot pairs, Physical Review Letters 99, 197402 (2007).

2006

• Electrically Tunable g Factors in Quantum Dot Molecular Spin States, Physical Review Letters 97, 197202 (2006).
• Engineering Electron and Hole Tunneling with Asymmetric InAs Quantum Dot Molecules, Applied Physics Letters 89, 233110 (2006).

2005

• Optical Pumping of the Electronic and Nuclear spin of Single Charge-Tunable Quantum Dots, Phys. Rev. Lett. 94, 047401 (2005).

2002

• Optical Studies of Single Quantum Dots, Physics Today, 55 (10), 36 (2002).

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