We study systematically the non-Markovian decoherence dynamics of a dissipative two-level system, i.e., the so-called spin-boson model. It is interesting to find that the decoherence tends to be inhibited with the increase of the coupling strength between the system and the reservoir, which is contrary to the common recognition that a stronger coupling always induces a severer decoherence. This is attributed to the occurrence of a quantum phase transition (QPT). The relationship between this QPT and conventional delocalized-localized QPT is also discussed. Our result suggests a useful control method to overcome the detrimental effects of the reservoir to the system.We study systematically the non-Markovian decoherence dynamics of a dissipative two-level system, i.e., the so-called spin-boson model. It is interesting to find that the decoherence tends to be inhibited with the increase of the coupling strength between the system and the reservoir, which is contrary to the common recognition that a stronger coupling always induces a severer decoherence. This is attributed to the occurrence of a quantum phase transition (QPT). The relationship between this QPT and conventional delocalized-localized QPT is also discussed. Our result suggests a useful control method to overcome the detrimental effects of the reservoir to the system.

arXiv:1208.4295Physical Review AMay 31, 201347 citations

Two-state system coupled to a boson mode: Quantum dynamics and classical approximations

R. Graham, M. H�hnerbach

The European Physical Journal BSep 1, 1984176 citations

Non-Markovianity of a two-level system transversally coupled to multiple bosonic reservoirs

Zhong‐Xiao Man, Nguyen Ba An, Yun‐Jie Xia

Dynamics of a two-level open system transversally coupled to a single zero-temperature bosonic reservoir may be Markovian or non-Markovian, depending on whether the system-reservoir coupling is weak or strong. In this paper, we show that when the system is simultaneously coupled to $N$ reservoirs its dynamics is always non-Markovian, provided that $N\ensuremath{\ge}{N}_{\mathrm{cr}},$ with ${N}_{\mathrm{cr}}$ a critical number depending on the reservoirs' parameters. Quantitatively, the non-Markovianity $\mathcal{N}$ is shown proportional to the number of contributed reservoirs. We explain our results in terms of the pseudomode theory, finding out that when $N\ensuremath{\ge}{N}_{\mathrm{cr}}$ the pseudomodes of all the reservoirs can always partially return information back to the system, no matter how strong the couplings between the system and each individual reservoir.Dynamics of a two-level open system transversally coupled to a single zero-temperature bosonic reservoir may be Markovian or non-Markovian, depending on whether the system-reservoir coupling is weak or strong. In this paper, we show that when the system is simultaneously coupled to $N$ reservoirs its dynamics is always non-Markovian, provided that $N\ensuremath{\ge}{N}_{\mathrm{cr}},$ with ${N}_{\mathrm{cr}}$ a critical number depending on the reservoirs' parameters. Quantitatively, the non-Markovianity $\mathcal{N}$ is shown proportional to the number of contributed reservoirs. We explain our results in terms of the pseudomode theory, finding out that when $N\ensuremath{\ge}{N}_{\mathrm{cr}}$ the pseudomodes of all the reservoirs can always partially return information back to the system, no matter how strong the couplings between the system and each individual reservoir.

Physical Review ADec 1, 201448 citations

Excitation of a two-level system damped by the interaction with bosons

Jan Loos

Czechoslovak Journal of PhysicsJun 1, 19721 citation

Dynamics of quantum Fisher information in a two-level system coupled to multiple bosonic reservoirs

Guoyou Wang, You-neng Guo, Ke Zeng

We consider the optimal parameter estimation for a two-level system coupled to multiple bosonic reservoirs. By using quantum Fisher information (QFI), we investigate the effect of the Markovian reservoirs’ number N on QFI in both weak and strong coupling regimes for a two-level system surrounded by N zero-temperature reservoirs of field modes initially in the vacua. The results show that the dynamics of QFI non-monotonically decays to zero with revival oscillations at some time in the weak coupling regime depending on the reservoirs’ parameters. Furthermore, we also present the relations between the QFI flow, the flows of energy and information, and the sign of the decay rate to gain insight into the physical processes characterizing the dynamics.We consider the optimal parameter estimation for a two-level system coupled to multiple bosonic reservoirs. By using quantum Fisher information (QFI), we investigate the effect of the Markovian reservoirs’ number N on QFI in both weak and strong coupling regimes for a two-level system surrounded by N zero-temperature reservoirs of field modes initially in the vacua. The results show that the dynamics of QFI non-monotonically decays to zero with revival oscillations at some time in the weak coupling regime depending on the reservoirs’ parameters. Furthermore, we also present the relations between the QFI flow, the flows of energy and information, and the sign of the decay rate to gain insight into the physical processes characterizing the dynamics.

Chinese Physics BNov 1, 20159 citations

N

reservoirs its dynamics is always non-Markovian, provided that $N\ensuremath{\ge}{N}_{\mathrm{cr}},$ with

{N}_{\mathrm{cr}}

a critical number depending on the reservoirs' parameters. Quantitatively, the non-Markovianity

\mathcal{N}

is shown proportional to the number of contributed reservoirs. We explain our results in terms of the pseudomode theory, finding out that when $N\ensuremath{\ge}{N}_{\mathrm{cr}}$ the pseudomodes of all the reservoirs can always partially return information back to the system, no matter how strong the couplings between the system and each individual reservoir.