In this paper we investigate an environmental effects to Josephson charge qubit (JCQ) when the environmentis taken as the Ohmic bath.At first,we derive the master equation from a JCQ-bath model.Then we investigate the...In this paper we investigate an environmental effects to Josephson charge qubit (JCQ) when the environmentis taken as the Ohmic bath.At first,we derive the master equation from a JCQ-bath model.Then we investigate thecoefficients of the equations that describe the shift in frequency,diffusive,decoherence,and so on.It is shown that ourresult on decoherence agrees with experimental one very well as the time is short enough.展开更多
In this paper the master equation method is used to calculate the relaxation and decoherence times of a qubit. The results are beyond Markovian approximation, where the noise spectrum is assumed to be wide-band, so th...In this paper the master equation method is used to calculate the relaxation and decoherence times of a qubit. The results are beyond Markovian approximation, where the noise spectrum is assumed to be wide-band, so that they are valid for not only the wide- but also the narrow-band noises, which may be the main decoherence source in solid-state qubits. Moreover, for some special cases, analytical results can be achieved, which are consistent with those derived by others.展开更多
We study the entanglement dynamics between two strongly-AC-driven superconducting charge qubitscoupled collectively to a zero temperature,dissipative resonator and find an unusual feather that the competing ofcreation...We study the entanglement dynamics between two strongly-AC-driven superconducting charge qubitscoupled collectively to a zero temperature,dissipative resonator and find an unusual feather that the competing ofcreation and annihilation of entanglement can lead to entanglement increasing,sudden death and revival.We alsocalculate the dependence of the death time on the initial state of the system.展开更多
基金National Natural Science Foundation of China under Grant No.10675066K.C.Wong Magna Foundation in Ningbo University
文摘In this paper we investigate an environmental effects to Josephson charge qubit (JCQ) when the environmentis taken as the Ohmic bath.At first,we derive the master equation from a JCQ-bath model.Then we investigate thecoefficients of the equations that describe the shift in frequency,diffusive,decoherence,and so on.It is shown that ourresult on decoherence agrees with experimental one very well as the time is short enough.
基金Project supported by the SRFDPthe PCSIRT+2 种基金the NFRPC (Grant No 2006CB921205)the National Natural Science Foundation of China (Grant Nos 10534060 and 10625416)the State Key Program for Basic Research of China (Grant Nos 2006CB921801and 2006CB921106)
文摘In this paper the master equation method is used to calculate the relaxation and decoherence times of a qubit. The results are beyond Markovian approximation, where the noise spectrum is assumed to be wide-band, so that they are valid for not only the wide- but also the narrow-band noises, which may be the main decoherence source in solid-state qubits. Moreover, for some special cases, analytical results can be achieved, which are consistent with those derived by others.
基金Supported by Hunan Provincial Natural Science Foundation of China under Grant No. 10J J6010the Key Project Foundation and the Youngth Foundation of Education Commission of Hunan Province of China under Grant Nos. 10A095, 09B079the Youth Foundation from Huaihua University of China under Grant No. HHUQ2009-09
文摘We study the entanglement dynamics between two strongly-AC-driven superconducting charge qubitscoupled collectively to a zero temperature,dissipative resonator and find an unusual feather that the competing ofcreation and annihilation of entanglement can lead to entanglement increasing,sudden death and revival.We alsocalculate the dependence of the death time on the initial state of the system.
