Research PapersNo Access

THE LOSS OF FIDELITY DUE TO QUANTUM LEAKAGE FOR JOSEPHSON CHARGE QUBITS

XIAN-TING LIANG

Department of Physics and Institute of Modern Physics, Ningbo University, Ningbo 315211, P. R. China

Corresponding author.

Search for more papers by this author

and

YONG-JIAN XIONG

Department of Physics and Institute of Modern Physics, Ningbo University, Ningbo 315211, P. R. China

Search for more papers by this author

https://doi.org/10.1142/S0217984905008268Cited by:2 (Source: Crossref)

Abstract

In this paper we calculate the loss of fidelity due to quantum leakage for the Josephson charge qubit (JCQ). In this investigation the characteristic values and characteristic states of the Mathieu equation are used. It is shown that for present typical parameters of JCQ, E_J/E_ch ~ 0.02, the loss of the fidelity per elementary operation is about 10^-4 which satisfies DiVincenzo's low decoherence criterion. By appropriately improving the designs of the Josephson junction, namely, decreasing E_J/E_ch to ~ 0.01, the loss of fidelity per elementary operation can decrease even smaller to 10^-5. The first-order nonadiabatic correction is also obtained by using the approach.

Keywords:

PACS: 03.67.Lx, 85.25.Cp

References

S. Lloyd, Science 261 (1993); D. P. DiVincenzo, ibid. 269 (1995) 255 . Google Scholar
C. Monroeet al., Phys. Rev. Lett. 75, 4714 (1995). Crossref, Web of Science, ADS, Google Scholar
Q. A. Turchetteet al., Phys. Rev. Lett. 75, 4710 (1995). Crossref, Web of Science, ADS, Google Scholar
N. A. Gershenfeld and I. L. Chuang, Science 275, 350 (1997). Crossref, Web of Science, Google Scholar
D. Loss and D. P. DiVincenzo, Phys. Rev. A57, 120 (1998). ADS, Google Scholar
A. Shnirman, G. Schön and Z. Hermon, Phys. Rev. Lett. 79, 2371 (1997). Crossref, Web of Science, ADS, Google Scholar
Y. Makhlin, G. Schön and A. Shnirman, Rev. Mod. Phys. 73, 357 (2001). Crossref, Web of Science, ADS, Google Scholar
R. Fazio, G. M. Palma and J. Siewert, Phys. Rev. Lett. 83, 5385 (1999). Crossref, Web of Science, ADS, Google Scholar
R. Fazioet al., Physica B284–288, (2000). Google Scholar
L.-A. Wu, M. S. Byrd and D. A. Lidar, Phys. Rev. Lett. 89, 127901 (2002). Crossref, Web of Science, ADS, Google Scholar
C. P. Sun, S. Yi and L. You, Phys. Rev. A67, 063815 (2003). Google Scholar
D. P. DiVincenzo , Mesoscopic Electron Transport , NATO ASI Series E , eds. L. Kowenhoven , G. Schön and L. Sohn ( Kluwer Ac. Publ. , Dordrecht , 1997 ) . Crossref, Google Scholar
E. Mathieu, J. Math. Pure Appl. 13, 137 (1868). Google Scholar
M. Abramowitz and I. A. Stegum , Handbook of Mathematical Functions ( Dover , New York , 1965 ) . Google Scholar
D. Frenkel and R. Portugal, J. Phys. 34, 3541 (2001). ADS, Google Scholar
G. Grignaniet al., Phys. Rev. B61, 11676 (2000). Crossref, Web of Science, ADS, Google Scholar
Y. Shi and Y. S. Wu, Phys. Rev. A69, 024301 (2004). Google Scholar
X. Wang, M. Keiji, H. Fan and Y. Nakamura, quant-ph/0112026 . Google Scholar
X. Hu and S. D. Sarma, Phys. Rev. A66, 012312 (2002). Google Scholar
M. Nielsen and I. Chuang , Quantum Computation and Quantum Information ( Cambridge University Press , Cambridge , 2000 ) . Google Scholar
X. T. Liang, quant-ph/0405188; X. T. Liang and Y. J. Xiong, Phys. Lett. A332 (2004) 8, quant-ph/0409102 . Google Scholar