Macroscopic Quantum Coherence Team
Team Leader
Jaw-Shen TSAI (Ph.D.)
We are studying macroscopic quantum coherence that occurs in small Josephson junction circuits. In the system, charge and phase degrees of freedoms co-exist, and their coherent control can be exploited as quantum bit (qubit), the basic component of the quantum computer. We have demonstrated such coherence in the superconducting system in 1999, and subsequently pioneered the superconducting solid state qubit technology. So far, we have demonstrated the operation of a 2-qubit-quantum logic gate, first time by a solid-state system. A highly efficient single-shot measurement was also demonstrated. The solid-state system is considered indispensable in realizing the integration required for a practical quantum computer. Recently, we have successfully demonstrated the execution of a small scale quantum protocol by developing a universal set of quantum logic gates with a qubit-coupling switch. Superconducting qubit behaves like an atom and it can be considered as an artificial atom. We are carrying out quantum optics experiments using such artificial atoms.
- Quantum coherence in superconducting circuit
- Quantum bit
- Quantum information processing
- RIKEN Advanced Science Institute Website_Laboratories Page
- Quantum cybernetics Page
- FIRST Quantum Information Processing Project Page
- May 10, 2010
- New quantum optical device with superconductive artificial atoms developed
- November 04,2011
- Putting artificial atoms on the clock
Artificial atoms give insight into how real atoms interact with light in real time
- A. A. Abdumalikov, Jr., O.V. Astafiev, Yu.A. Pashkin, Y. Nakamura and J. S. Tsai.:
"Dynamics of Coherent and Incoherent Emission from an Artificial Atom in a 1D Space"
Phys. Rev. Lett. 107, 043604 (2011) - J. Bylander, S. Gustavsson, F. Yan, F. Yoshihara, K. Harrabi, G. Fitch, D.G. Cory, Y. Nakamura, J.S Tsai & W.D. Oliver.:
"Noise spectroscopy through dynamical decoupling with a superconducting flux qubit"
Nature Physics Vol.7, 565-570 (2011) - O.Astafiev. ,A.A.Abdumalikov Jr., A.M.Zagoskin, Yu. A.Paskin,Y.Nakamura and J.S.Tsai.:
"Ultimate On-Chip Quantum Amplifier"
Phys. Rev. Lett. 104, 183603(2010) - A.A.Abdumalikov Jr., O.Astafiev. , A.M.Zagoskin, Yu. A.Paskin,Y.Nakamura and J. S.Tsai.:
"Electromagnetically induced transparency on a single artificial atom"
Phys. Rev. Lett. 104, 193601(2010) - O.Astafiev. A.M.Zagoskin,A.A.Abdumalikov Jr., Yu. A.Paskin,T.Yamamoto,K.Inomata,Y.Nakamura,J.S.Tsai.:
"Resonance Fluorescence of a Single Artificial Atom"
Science, 327, 840 (2010) - Astafiev, O., Inomata, K., Niskanen, A. O., Yamamoto, T., Pashkin, Yu. A., Nakamura, Y. and Tsai, J. S.:
"Single artificial-atom lasing"
Nature, 449, 588 (2007) - Niskanen, A. O., Harrabi, K., Yoshihara, F., Nakamura, Y., Lloyd, S. and Tsai, J. S.:
"Quantum Coherent Tunable Coupling of Superconducting Qubits"
Science, 316, 723 (2007) - Yoshihara, F., Harrabi, K., Niskanen, A. O., Nakamura, Y., and Tsai, J. S.:
"Decoherence of Flux Qubits due to 1/f Flux Noise"
Physical Review Letters, 97, 167001 (2006) - Yamamoto, T., Pashkin, Yu. A., Astafiev, O., Nakamura, Y., and Tsai, J. S.:
"Demonstration of conditional gate operation using superconducting charge qubits"
Nature 425, 941 (2003). - Pashkin, Yu. A., Yamamoto, T., Astafiev, O., Nakamura, Y., Averin, D. V., and Tsai, J. S.:
"Quantum oscillation in two coupled charge qubit"
Nature 421, 823 (2003).
Principal Investigator
- Jaw-Shen TSAI
- Team Leader
Staff Scientist
- Yuri PASHKIN
- Research Scientist
- Oleg V. ASTAFIEV
- Research Scientist
- Fumiki YOSHIHARA
- ASI Research Scientist
- Kunihiro INOMATA
- ASI Research Scientist
- Toshiyuki MIYAZAKI
- ASI Research Scientist
Postdoctoral Fellow
- Pierre-Marie BILLANGEON
- Foreign Postdoctoral Researcher
- Zhihui PENG
- Postdoctoral Researcher
- Sergey KAFANOV
- Postdoctoral Researcher
- Joonas Tapio PELTONEN
- Postdoctoral Researcher
- Zhirong LIN
- Postdoctoral Researcher