Physics, mathematics, and technology

2012 Issue №4

Back to the list Download the article

On interaction of a qubit with a fluctuating environment



It is shown that the equations of Gurvitz and Mozyrsky for a system consisting of a qubit interacting with a fluctuating environment in certain conditions are reduced to evolution equations of the qubit. Such evolution equations for the qubit can be generalized to the form, which implies the existence of entangled states of the combined system. Among these entangled states two are symmetric, and two — antisymmetric. One symmetric state is stationary.


1. Leggett A. J., Chakravarty S., Dorsey A. T. et al. Dynamics of the dissipative twolevel system // Rev. Mod. Phys. 1987. Vol. 59, № 1.
2. Weiss U. Quantum Dissipative Systems // World Scientific. Singapure, 2000.
3. Shnirman A., Makhlin Y., Schoon G. Noise and Decoherence in quantum twolevel systems // Phys. Scr. 2002. Vol. 102, № 147.
4. Gassmann H., Marquardt F., Bruder C. Non-Markovian effects of a simple nonlinear bath // Phys. Rev. 2002. Vol. E 66. P. 041111.
5. Paladino E., Faoro L., Falci G., Fazio R. Suppression of noise in one-qubit systems // Phys. Rev. Lett. 2002. Vol. 88. P. 228304.
6. Gurvitz S. A. Measurements with a noninvasive detector and dephasing mechanism // Phys. Rev. 1997. Vol. B 56. P. 15215.
7. Kack A., Wendin G., Johansson G. Full frequency voltage noise spectral density of a single electron transistor // Phys. Rev. 2003. Vol. B 67. P. 035301.
8. Gurvitz S. A., Mozyrsky D. Quantum mechanical approach to decoherence and relaxation generated by fluctuating environment // Phys. Rev. 2008. Vol. B 77. P. 075325.
9. Иванов А. И., Иванов А. А. Применение метода эффективного гамильтониана в динамике открытых квантовых систем // Вестник Российского государственного университета им. И. Канта. Вып. 4. Калининград, 2009. С. 25.
10. Иванов А. И., Иванов А. А. Оценка ошибок детектирования состояний кубита // Вестник Балтийского федерального университета им. И. Канта. Вып. 5. Калининград, 2011. С. 17.