Non-Markovian time evolution of an accelerated qubit

Moustos, Dimitris; Anastopoulos, Charis

doi:10.1103/physrevd.95.025020

Cited by 51 publications

(70 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a perspective, it should be interesting to go beyond the Born-Markov approximation, and to see whether a similar argument for the relaxation of the detectors to equilibrium (Gibbs or frequency-dependent thermal) states can be obtained. In the case of the Unruh effect it has been found in [11] that the late-time asymptotic state of the detector is a Gibbs thermal state even if non-Markovian effects are taken into account. This suggests that it is plausible that a similar conclusion can be reached for detectors interacting with fields in arbitrary KMS states.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Asymptotic states for stationary Unruh-DeWitt detectors

Juárez-Aubry

Moustos

2019

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

We study the late-time asymptotic state of a stationary Unruh-DeWitt detector interacting with a field in a thermal state. We work in an open system framework, where the field plays the role of an environment for the detector. The long-time interaction between the detector and the field is modelled with the aid of a one-parameter family of switching functions that turn on and off the interaction Hamiltonian between the two subsystems, such that the long-time interaction limit is reached as the family parameter goes to infinity. In such limit, we show that if the field is in a Kubo-Martin-Schwinger (KMS) state and the detector is stationary with respect to the notion of positive frequency of the field, in the Born-Markov approximation, the asymptotic state of the detector is a Gibbs state at the KMS temperature. We then relax the KMS condition for the field state, and require only that a frequencydependent version of the detailed balance condition for the Wightman function pulled back to the detector worldline hold, in the sense that the inverse temperature appearing in the detailed balance relation need not be constant. In this setting, we show that the late-time asymptotic state of the detector has the form of a thermal density matrix, but with a frequency-dependent temperature. We present examples of these results, which include the classical Unruh effect and idealised Hawking radiation (for fields in the HHI state), and also the study of the late-time behaviour of detectors following stationary "cusped" and circular motions in Minkowski space interacting with a massless Klein-Gordon field in the Minkowski vacuum. In the cusped motion case, a frequency-dependent, effective temperature for the asymptotic late-time detector state is obtained analytically. In the circular motion case, such effective temperature is obtained numerically. * Electronic address: benito.juarez@iimas.unam.mx † Electronic address: dmoustos@upatras.gr

show abstract

Section: Discussionmentioning

confidence: 99%

“…A word on the Markov approximation is due. In [11] the role played by non-Markovian effects in the Unruh effect has been studied. In particular, in Sec.…”

Section: Time Evolution Of the Detector In The Born-markov Appromentioning

confidence: 99%

Asymptotic states for stationary Unruh-DeWitt detectors

Juárez-Aubry

Moustos

2019

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

show abstract

“…Nevertheless, such approximation can be eliminated to further include possible back-action of the detector to the field and the spontaneous emission after excitations, i.e., incorporating non-Markovian effects [62]. Such effect may be significant in the early-time behavior of FI/QFI, when the detector does not exhibit a thermal behavior as non-Markovian effects are taken into account [63].…”

Section: Discussionmentioning

confidence: 99%

Quantum estimation in an expanding spacetime

Huang¹,

Feng²,

Zhang³

et al. 2018

Annals of Physics

View full text Add to dashboard Cite

We investigate the quantum estimation on the Hubble parameter of an expanding de Sitter space by quantum metrological techniques. By exploring the dynamics of a freely falling Unruh-DeWitt detector, which interacts with a scalar field coupling to curvature, we calculate the Fisher information (FI) and quantum Fisher information (QFI) for the detector, which bound the highest precision of the estimation on Hubble parameter. In standard Bunch-Davies vacuum, we show that the maxima of FI/QFI are located for particular initial state of probe. Beside its dependence on the evolving time of detector and the energy spacing of atom ω, we show that the maxima of FI/QFI can be significantly enhanced once a proper coupling of scalar field to curvature is chosen. For instance, we show numerically that the estimation in the scenario with minimally/nearly minimally coupling scalar field can always outperform that with conformally coupling scalar field, corresponding to a higher FI/QFI in estimation. Moreover, we find that for general α−vacua of de Sitter space, a further improvement of estimation can be achieved, attributed to the squeezed nature of α−vacua that heavily constrains the measurement uncertainty. Some implications of our results are also discussed.

show abstract

“…This work accompanies a companion paper [21], which uses these tools to track the late-time evolution of an Unruh-DeWitt detector [22,23]: a simple two-level system (or qubit) as it uniformly accelerates in flat space while coupled to a simple quantum scalar field (prepared in its Minkowski vacuum). Such a simple system allows these open-system tools to be explored in a very concrete and explicit way (see also [24][25][26][27][28][29][30][31][32][33][34][35]). Ref.…”

Section: Introductionmentioning

confidence: 99%

Hot cosmic qubits: late-time de Sitter evolution and critical slowing down

Kaplanek

Burgess

2020

J. High Energ. Phys.

View full text Add to dashboard Cite

Temporal evolution of a comoving qubit coupled to a scalar field in de Sitter space is studied with an emphasis on reliable extraction of late-time behaviour. The phenomenon of critical slowing down is observed if the effective mass is chosen to be sufficiently close to zero, which narrows the window of parameter space in which the Markovian approximation is valid. The dynamics of the system in this case are solved in a more general setting by accounting for non-Markovian effects in the evolution of the qubit state. Self-interactions for the scalar field are also incorporated, and reveal a breakdown of late-time perturbative predictions due to the presence of secular growth.

show abstract

Non-Markovian time evolution of an accelerated qubit

Cited by 51 publications

References 36 publications

Asymptotic states for stationary Unruh-DeWitt detectors

Asymptotic states for stationary Unruh-DeWitt detectors

Quantum estimation in an expanding spacetime

Hot cosmic qubits: late-time de Sitter evolution and critical slowing down

Contact Info

Product

Resources

About