Principal Investigators: Dr. Daniel Gammon, Dr. Allan S. Bracker

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.

Selected Publications

2013 Yakes, M. K., L. Yang, A. Bracker, T. M. Sweeney, P. G. Brereton, M. Kim, C. S. Kim, P. M. Vora, D. Park, S. G. Carter, et al., "Leveraging crystal anisotropy for deterministic growth of InAs quantum dots with narrow optical linewidths", Nano Letters, vol. 13, issue 10, pp. 4870-4875, 2013. nl402744s.pdf (3.82 MB)
2013 Greilich, A., S. C. Badescu, D. Kim, A. Bracker, and D. Gammon, "Optical Measurement and Modeling of Interactions between Two Hole Spins or Two Electron Spins in Coupled InAs Quantum Dots", Physical Review Letters, vol. 110, issue 11, 2013. e117402.pdf (853.13 KB)
2013 Carter, S. G., T. M. Sweeney, M. Kim, C. S. Kim, D. Solenov, S. Economou, T. Reinecke, L. Yang, A. Bracker, and D. Gammon, "Quantum control of a spin qubit coupled to a photonic crystal cavity", Nature Photonics, vol. 7, issue 4, 2013. Carter PhC qubit.pdf (992.15 KB)
2011 Greilich, A., S. G. Carter, D. Kim, A. Bracker, and D. Gammon, "Optical control of one and two hole spins in interacting quantum dots", Nature Photonics, vol. 5, issue 11, pp. 703-709, 2011. 11-1226-3607.pdf (247.3 KB)
2010 Yakes, M. K., C. D. Cress, J. G. Tischler, and A. Bracker, "Three-Dimensional Control of Self-Assembled Quantum Dot Configurations", ACS Nano, vol. 4, issue 7, pp. 3877-3882, 2010. 10-1226-2510.pdf (317.94 KB)
2009 Doty, M. F., J. I. Climente, M. Korkusinski, M. Scheibner, A. Bracker, P. Hawrylak, and D. Gammon, "Antibonding ground states in InAs quantum dot molecules", Physical Review Letters, vol. 102, 2009. 08-1226-4126.pdf (2.04 MB)
2008 Kim, D., S. Economou, S. C. Badescu, M. Scheibner, A. Bracker, M. Bashkansky, T. Reinecke, and D. Gammon, "Optical spin spin initialization and nondestructive measurement in a quantum dot molecule", Physical Review Letters, vol. 101, 2008. 08-1226-3576.pdf (1.08 MB)
2008 Scheibner, M., M. K. Yakes, A. Bracker, I. V. Ponomarev, M. F. Doty, C. S. Hellberg, L. J. Whitman, T. Reinecke, and D. Gammon, "Optically mapping the electronic structure of coupled quantum dots", Nature Physics, vol. 4, 2008. 08-1226-0001.pdf (1.18 MB)
2007 Scheibner, M., I. V. Ponomarev, E. A. Stinaff, M. F. Doty, A. Bracker, C. S. Hellberg, T. Reinecke, and D. Gammon, "Photoluminescence spectroscopy of the molecular biexciton in vertically stacked InAs-GaAs quantum dot pairs", Physical Review Letters, vol. 99, 2007. 07-1226-3326.pdf (1.15 MB)
2006 Doty, M. F., M. Scheibner, I. V. Ponomarev, E. A. Stinaff, A. Bracker, V. L. Korenev, T. Reinecke, and D. Gammon, "Electrically Tunable g Factors in Quantum Dot Molecular Spin States", Physical Review Letters, vol. 97, 2006. 06-1226-3198.pdf (760 KB)
2006 Bracker, A., M. Scheibner, M. F. Doty, E. A. Stinaff, I. V. Ponomarev, J. Kim, L. J. Whitman, T. Reinecke, and D. Gammon, "Engineering Electron and Hole Tunneling with Asymmetric InAs Quantum Dot Molecules", Applied Physics Letters, vol. 89, 2006. 06-1226-3026.pdf (324.85 KB)
2005 Bracker, A., E. A. Stinaff, D. Gammon, M. E. Ware, J. G. Tischler, A. Shabaev, A. L. Efros, D. Park, D. Gershoni, V. L. Korenev, et al., "Optical Pumping of the Electronic and Nuclear spin of Single Charge-Tunable Quantum Dots", Physical Review Letters, vol. 94, 2005. 04-1226-1081.pdf (177.85 KB)
2002 Gammon, D., and D. G. Steel, "Optical Studies of Single Quantum Dots", Physics Today, vol. 55, issue 10, 2002. 02-1221.1-3008.pdf (1.16 MB)