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Zeno dynamics in quantum open systems.

Zhang YR, Fan H - Sci Rep (2015)

Bottom Line: We firstly study the consequences of non-Markovian noise on quantum Zeno effect and give the exact forms of the dissipative Fisher information and the quantum Zeno time.Then, for the operator-sum representation, an achievable upper bound of the quantum Zeno time is given with the help of the results in noisy quantum metrology.It is of significance that the noise reducing the accuracy in the entanglement-enhanced parameter estimation can conversely be favorable for the accessibility of quantum Zeno dynamics of entangled states.

View Article: PubMed Central - PubMed

Affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.

ABSTRACT
Quantum Zeno effect shows that frequent observations can slow down or even stop the unitary time evolution of an unstable quantum system. This effect can also be regarded as a physical consequence of the statistical indistinguishability of neighboring quantum states. The accessibility of quantum Zeno dynamics under unitary time evolution can be quantitatively estimated by quantum Zeno time in terms of Fisher information. In this work, we investigate the accessibility of quantum Zeno dynamics in quantum open systems by calculating noisy Fisher information when a trace preserving and completely positive map is assumed. We firstly study the consequences of non-Markovian noise on quantum Zeno effect and give the exact forms of the dissipative Fisher information and the quantum Zeno time. Then, for the operator-sum representation, an achievable upper bound of the quantum Zeno time is given with the help of the results in noisy quantum metrology. It is of significance that the noise reducing the accuracy in the entanglement-enhanced parameter estimation can conversely be favorable for the accessibility of quantum Zeno dynamics of entangled states.

No MeSH data available.


Related in: MedlinePlus

The first derivative of decay rate for t = 0 agianst s.Parameters are set as α = 0.01 and ωc = 3. Three cases with three temperatures T = 0, 4 and 8 are plotted by blue solid line, red dashed line and black dot-dashed line, respectively.
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f1: The first derivative of decay rate for t = 0 agianst s.Parameters are set as α = 0.01 and ωc = 3. Three cases with three temperatures T = 0, 4 and 8 are plotted by blue solid line, red dashed line and black dot-dashed line, respectively.

Mentions: where is the Hurwitz zeta function (a generalized Riemann zeta function). The d-FI and d-ZT may be calculated as and , where first derivative of decay rate for t = 0 is shown in Fig. 1 given the parameters α = 0.005 and ωc = 3. It is shown that, as the temperature of bath becomes higher, increases, which makes the quantum Zeno dynamics more difficult. Moreover, we find that for a definite temperature T, declines first and increases then as s increases. Thus, to realize the Zeno dynamics for this model depends on the temperature and the spectral density function of the bath.


Zeno dynamics in quantum open systems.

Zhang YR, Fan H - Sci Rep (2015)

The first derivative of decay rate for t = 0 agianst s.Parameters are set as α = 0.01 and ωc = 3. Three cases with three temperatures T = 0, 4 and 8 are plotted by blue solid line, red dashed line and black dot-dashed line, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477237&req=5

f1: The first derivative of decay rate for t = 0 agianst s.Parameters are set as α = 0.01 and ωc = 3. Three cases with three temperatures T = 0, 4 and 8 are plotted by blue solid line, red dashed line and black dot-dashed line, respectively.
Mentions: where is the Hurwitz zeta function (a generalized Riemann zeta function). The d-FI and d-ZT may be calculated as and , where first derivative of decay rate for t = 0 is shown in Fig. 1 given the parameters α = 0.005 and ωc = 3. It is shown that, as the temperature of bath becomes higher, increases, which makes the quantum Zeno dynamics more difficult. Moreover, we find that for a definite temperature T, declines first and increases then as s increases. Thus, to realize the Zeno dynamics for this model depends on the temperature and the spectral density function of the bath.

Bottom Line: We firstly study the consequences of non-Markovian noise on quantum Zeno effect and give the exact forms of the dissipative Fisher information and the quantum Zeno time.Then, for the operator-sum representation, an achievable upper bound of the quantum Zeno time is given with the help of the results in noisy quantum metrology.It is of significance that the noise reducing the accuracy in the entanglement-enhanced parameter estimation can conversely be favorable for the accessibility of quantum Zeno dynamics of entangled states.

View Article: PubMed Central - PubMed

Affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.

ABSTRACT
Quantum Zeno effect shows that frequent observations can slow down or even stop the unitary time evolution of an unstable quantum system. This effect can also be regarded as a physical consequence of the statistical indistinguishability of neighboring quantum states. The accessibility of quantum Zeno dynamics under unitary time evolution can be quantitatively estimated by quantum Zeno time in terms of Fisher information. In this work, we investigate the accessibility of quantum Zeno dynamics in quantum open systems by calculating noisy Fisher information when a trace preserving and completely positive map is assumed. We firstly study the consequences of non-Markovian noise on quantum Zeno effect and give the exact forms of the dissipative Fisher information and the quantum Zeno time. Then, for the operator-sum representation, an achievable upper bound of the quantum Zeno time is given with the help of the results in noisy quantum metrology. It is of significance that the noise reducing the accuracy in the entanglement-enhanced parameter estimation can conversely be favorable for the accessibility of quantum Zeno dynamics of entangled states.

No MeSH data available.


Related in: MedlinePlus