Transmon

In quantum computing, a transmon is a type of superconducting charge qubit that is designed to have reduced sensitivity to charge noise. The transmon was developed by scientists at Yale University in 2007.[1][2] Its name is an abbreviation of the term transmission line shunted plasma oscillation qubit.

The transmon achieves its reduced sensitivity to charge noise by significantly increasing the ratio of the Josephson energy to the charging energy. This is accomplished through the use of a large shunting capacitor. The result is energy level spacings that are approximately independent of offset charge. Typical transmon qubits have T2 coherence times ~ 1 μs.[3] By replacing the superconducting transmission line cavity with a three-dimensional superconducting cavity, recent work on transmon qubits has shown significantly improved T2 times, as long as 95 μs.[4][5] These results demonstrate that previous T2 times were not limited by Josephson junction losses. Understanding the fundamental limits on the coherence time in superconducting qubits such as the transmon is an active area of research.

See also

References

  1. ↑ J. Koch et al., "Charge-insensitive qubit design derived from the Cooper pair box," Phys. Rev. A 76, 04319 (2007), doi:10.1103/PhysRevA.76.042319, arXiv:0703002
  2. ↑ J.A. Schreier et al., "Suppressing charge noise decoherence in superconducting charge qubits," Phys. Rev. B 77, 180502 (2008), doi:10.1103/PhysRevB.77.180502, arXiv:0712.3581
  3. ↑ A.A. Houck et al., "Life after charge noise: recent results with transmon qubits," Quant. Inf. Proc. 8, 105 (2009), doi:10.1007/s11128-009-0100-6, arXiv:0812.1865
  4. ↑ H. Paik et al., "Observation of high coherence in Josephson junction qubits measured in a three-dimensional circuit QED architecture," Phys. Rev. Lett. 107, 240501 (2011), doi:10.1103/PhysRevLett.107.240501, arXiv:1105.4652
  5. ↑ C. Rigetti et al., "Superconducting qubit in waveguide cavity with coherence time approaching 0.1 ms," Phys. Rev. B 86, 100506(R) (2012), doi:10.1103/PhysRevB.86.100506, arXiv:1202.5533