Quantum dots Charge qubit

Home Research topics Publication list Group members Facilities Access Oppotunities Japanese >>Quantum dots/Charge qubit >>Two-dimensional system >>Low-temperature nanoprobe Quantum Dots/Charge Qubit We investigate single-electron transport, correlated transport, and time-dependent phenomena in quantum dots (GaAs, Si, carbon based molecules, etc.). We are developing quantum information technology based on electron charge and spin. Figure: Correlated Coherent Oscillations in Coupled Semiconductor Charge Qubits [Phys. Rev. Lett. 103, 056802 (2009)]. Selected publications Single-electron dynamics and qubit Wide-band capacitance measurement on a semiconductor double quantum dot for studying tunneling dynamics Takeshi Ota, Toshiaki Hayashi, Koji Muraki and Toshimasa Fujisawa Appl. Phys. Lett. 96, 032104 (2010). Correlated Coherent Oscillations in Coupled Semiconductor Charge Qubits G. Shinkai, T. Hayashi, T. Ota, and T. Fujisawa Phys. Rev. Lett. 103, 056802 (2009). Controlled resonant tunneling in a coupled double-quantum-dot system G. Shinkai, T. Hayashi, Y. Hirayama, and T. Fujisawa Appl. Phys. Lett. 90, 103116 (2007). Bidirectional counting of single electrons Toshimasa Fujisawa, T. Hayashi, R. Tomita, Y. Hirayama Science 312, 1634 (2006). Electrical pump-and-probe study of spin singlet-triplet relaxation in a quantum dot S. Sasaki, T. Fujisawa, T. Hayashi, and Y. Hirayama Phys. Rev. Lett. 95, 056803 (2005). Coherent manipulation of electronic states in a double quantum dot T. Hayashi, T. Fujisawa, H. D. Cheong, Y. H. Jeong, and Y. Hirayama Phys. Rev. Lett. 91, 226804 (2003). Allowed and forbidden transitions in artificial hydrogen and helium atoms T. Fujisawa, D. G. Austing, Y. Tokura, Y. Hirayama, and S. Tarucha Nature 419, 278 (2002). Kondo effect Spin-orbital Kondo effect in a parallel double quantum dot Yuma Okazaki, Satoshi Sasaki, and Koji Muraki Phys. Rev. B 84, 161305(R) (2011). Fano-Kondo Interplay in a Side-Coupled Double Quantum Dot S. Sasaki, H. Tamura, T. Akazaki, and T. Fujisawa Phys. Rev. Lett. 103, 266806 (2009). Non-local control of the Kondo effect in a double quantum dot-quantum wire coupled system S. Sasaki, S. Kang, K. Kitagawa, M. Yamaguchi, S. Miyashita, T. Maruyama, H. Tamura, T. Akazaki, Y. Hirayama, and H. Takayanagi Phys. Rev. B 73, 161303(R) (2006). Enhanced Kondo Effect via Tuned Orbital Degeneracy in a Spin-1/2 Artificial Atom S. Sasaki, T. Fujisawa, T. Hayashi, and Y. Hirayama Phys. Rev. Lett. 93, 17205 (2004). Kondo effect in an integer-spin quantum dot S. Sasaki, S. De Franceschi, J. Elzerman, W. van der Wiel, M. Eto, S. Tarucha, and L. P. Kouwenhoven Nature 405, 764 (2000). Other topics for GaAs quantum dot Observation of Hysteretic Transport due to Dynamic Nuclear Spin Polarization in a GaAs Lateral Double Quantum Dot Takashi Kobayashi, Kenichi Hitachi, Satoshi Sasaki, and Koji Muraki Phys. Rev. Lett. 107, 216802 (2011). Carbon nanotube and Si quantum dots Gate-Dependent Orbital Magnetic Moments in Carbon Nanotubes T. S. Jespersen, K. Grove-Rasmussen, K. Flensberg, J. Paaske, K. Muraki, T. Fujisawa, and J. Nygård Phys. Rev. Lett. 107, 186802 (2011). Gate-dependent spin-orbit coupling in multielectron carbon nanotubes T. S. Jespersen, K. Grove-Rasmussen, J. Paaske, K. Muraki, T. Fujisawa, J. Nygard and K. Flensberg Nature Phys. 7, 348 (2011). A Triple Quantum Dot in a Single-Wall Carbon Nanotube K. Grove-Rasmussen, H. I. J&orgensen, T. Hayashi, P. E. Lindelof, and T. Fujisawa Nano Lett. 8, 1055 (2008). Pauli-spin-blockade transport through a silicon double quantum dot H. W. Liu, T. Fujisawa, Y. Ono, H. Inokawa, A. Fujiwara, K. Takashina, and Y. Hirayama Phys. Rev. B 77, 073310 (2008). Molecular electronics Room-temperature stability of Pt nanogaps formed by self-breaking F. Prins, T. Hayashi, B. J. A. de Vos van Steenwijk, B. Gao, E. A. Osorio, K. Muraki, and H. S. J. van der Zant Appl. Phys. Lett. 94, 123108 (2009).

3-1 Morinosato-Wakamiya, Atugi, Kanagawa 243-0198, Japan Qauntum Solid State Physics Research Group Physical Science Labortory NTT Basic Research Laboratories NTT