Maximal quantum Fisher information in the semi-classical Rabi model

Chen, Jie; Wang, Zhihai; Liang, Hongbin; Wang, Xiaoguang

doi:10.1140/epjd/e2018-90024-0

Cited by 8 publications

(9 citation statements)

References 31 publications

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“…To solve the system, we need to extend the counter‐rotating hybridized rotating wave approximation (CHRWA) from a two‐level system to a su(2) system. [ 23–26 ] As a first step, the unitary transformation

{\overset{U}{true}}_{1} false(t false) = \exp false[i \frac{A}{ω} ξ \sin (ω t + ϕ) J_{x} false]

is introduced with ξ as a regulating variable. After the unitary evolution, the Hamiltonian becomes

\begin{matrix} true \\ right {\overset{H}{true}}_{1} & = & left ω_{0} ({} \cos [\frac{A}{ω} ξ \sin (() ω t + ϕ)] J_{z} + \sin [\frac{A}{ω} ξ \sin (() ω t + ϕ)] J_{y}) \\ left + A (() 1 - ξ) \cos (() ω t + ϕ) J_{x} \end{matrix}

…”

Section: Charging Efficiencies Of Qb Systems With Charging In One or mentioning

confidence: 99%

“…Note that

{\tilde{H}}_{1}

can be expanded as an infinite series with

\cos false(z \sin ϕ_{t} false) = J_{0} false(z false) + \sum_{k = 1}^{\infty} 2 J_{2 k} false(z false) \cos false(2 k ϕ_{t} false)

and

\sin false(z \sin ϕ_{t} false) = \sum_{k = 0}^{\infty} 2 J_{2 k + 1} false(z false) \sin false[(2 k + 1) ϕ_{t} false]

, where

J_{n} false(\cdot false)

is the Bessel function. If the higher‐order harmonic terms are neglected, the Hamiltonian can be approximated as [ 24–26 ]

\begin{matrix} true \\ right {\overset{H}{true}}_{1} & = & left ω_{0} J_{0} ((), \frac{A}{ω}, ξ) J_{z} + A (() 1 - ξ) \cos (() ω t + ϕ) J_{x} \\ left + 2 ω_{0} J_{1} ((), \frac{A}{ω}, ξ) \sin (() ω t + ϕ) J_{y}, \\ = & left ω_{0} J_{0} ((), \frac{A}{ω}, ξ) J_{z} + \overset{A}{true} ([] \cos (ω t + ϕ) J_{x} + \sin (ω t + ϕ) J_{y}) \end{matrix}

where

\tilde{A} = A false(1 - ξ false) = 2 ω_{0} J_{1} false(\frac{A}{ω} ξ false)

is regulated by ξ. Furthermore, the unitary evolution

{\overset{U}{true}}_{2} false(

…”

Section: Charging Efficiencies Of Qb Systems With Charging In One or mentioning

confidence: 99%

“…Furthermore, the unitary evolution

{\overset{U}{true}}_{2} false(t false) = \exp false[i (ω t + ϕ) J_{z} false]

makes the Hamiltonian time‐independent

{\overset{H}{true}}_{2} = \tilde{normalΔ} J_{z} + \tilde{A} J_{x}

where

\tilde{normalΔ} = ω_{0} J_{0} false(\frac{A}{ω} ξ false) - ω

is the effective detuning. [ 24–26 ]…”

Section: Charging Efficiencies Of Qb Systems With Charging In One or mentioning

confidence: 99%

See 2 more Smart Citations

Charging Quantum Batteries with a General Harmonic Driving Field

et al. 2020

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A general harmonic driving field was considered for improving the charging efficiency of the quantum battery system. Charge saturation was used to describe the charging efficiency, where the charging mode is divided into saturated and unsaturated. The relationships between the time-dependent charge saturation and parameters of the general driving field were evaluated both analytically and numerically. The Floquet theorem was used to express time-dependent charge saturation with the quasienergy and Floquet states of the system. The analytical and numerical results were used to identify the best parameter values for optimizing the charging efficiency.

show abstract

{\overset{U}{true}}_{1} false(t false) = \exp false[i \frac{A}{ω} ξ \sin (ω t + ϕ) J_{x} false]

is introduced with ξ as a regulating variable. After the unitary evolution, the Hamiltonian becomes

\begin{matrix} true \\ right {\overset{H}{true}}_{1} & = & left ω_{0} ({} \cos [\frac{A}{ω} ξ \sin (() ω t + ϕ)] J_{z} + \sin [\frac{A}{ω} ξ \sin (() ω t + ϕ)] J_{y}) \\ left + A (() 1 - ξ) \cos (() ω t + ϕ) J_{x} \end{matrix}

…”

Section: Charging Efficiencies Of Qb Systems With Charging In One or mentioning

confidence: 99%

“…Note that

{\tilde{H}}_{1}

can be expanded as an infinite series with

\cos false(z \sin ϕ_{t} false) = J_{0} false(z false) + \sum_{k = 1}^{\infty} 2 J_{2 k} false(z false) \cos false(2 k ϕ_{t} false)

and

\sin false(z \sin ϕ_{t} false) = \sum_{k = 0}^{\infty} 2 J_{2 k + 1} false(z false) \sin false[(2 k + 1) ϕ_{t} false]

, where

J_{n} false(\cdot false)

is the Bessel function. If the higher‐order harmonic terms are neglected, the Hamiltonian can be approximated as [ 24–26 ]

\begin{matrix} true \\ right {\overset{H}{true}}_{1} & = & left ω_{0} J_{0} ((), \frac{A}{ω}, ξ) J_{z} + A (() 1 - ξ) \cos (() ω t + ϕ) J_{x} \\ left + 2 ω_{0} J_{1} ((), \frac{A}{ω}, ξ) \sin (() ω t + ϕ) J_{y}, \\ = & left ω_{0} J_{0} ((), \frac{A}{ω}, ξ) J_{z} + \overset{A}{true} ([] \cos (ω t + ϕ) J_{x} + \sin (ω t + ϕ) J_{y}) \end{matrix}

where

\tilde{A} = A false(1 - ξ false) = 2 ω_{0} J_{1} false(\frac{A}{ω} ξ false)

is regulated by ξ. Furthermore, the unitary evolution

{\overset{U}{true}}_{2} false(

…”

Section: Charging Efficiencies Of Qb Systems With Charging In One or mentioning

confidence: 99%

See 1 more Smart Citation

Charging Quantum Batteries with a General Harmonic Driving Field

et al. 2020

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“…The deposited energy is recorded in concentric layers whose thickness is a fraction of the CSDA (Continuous Slowing Down Approximation) path of the primary electrons. The calculation of the dose kernel point (normalized and dimensionless quantity) is carried out according to the following formula [14] such as is the density of the material, Z is the atomic number, and A is the mass of the atom, k is the correction factor, J is the ionization energy, and dS is Bethe Surface. For COVID-19, Z, A, and J should be the average number of atoms, the average atomic mass, and the average ionization energy.…”

Section: Physicsmentioning

confidence: 99%

Monte Carlo Simulation Method Highlighting on the Electron Beam Irradiation on the Structure of SARS-CoV-2

et al. 2020

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The outbreak of SARS-CoV-2 resulted in more than 11 000 000 infections and over 530 000 deaths. Coronavirus (S) spike glycoproteins promote entry into cells and are the main target of antibodies. We studied the effect of electron beams on the SARS CoV-2 glycoprotein and also on RNA using Monte Carlo simulation. We demonstrated that S-SARS CoV peak glycoproteins damaged by irradiation electrons corresponding to an energy loss of approximately 1.2 keV with a damage rate of the efficiency that can be as high as .

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“…Over all of the advanced approaches, it is worth emphasizing the efficacy of the counter-rotating-hybridized rotatingwave method (CHRW method) [46], which has been extensively utilized in many researches [47][48][49][50][51][52][53][54]. In comparison with the classical Rabi-RWA method, it takes the effects of the CR terms into consideration by a unitary transformation, which results in the RWA mathematical formalism applicable to both the far off-resonant situation (∆ ≫ ω or ∆ ≪ ω) and the intermediate-strong driving strength case.…”

Section: Introductionmentioning

confidence: 99%

Plateau dynamics with quantized oscillations of a strongly driven qubit

Chen,

Lü,

Yan

et al. 2020

Preprint

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We present an interesting dynamical temporal localization of a strongly driven two-level system (TLS), a plateau with quantized oscillation, by an analytical and transparent method, the counterrotating-hybridized rotating-wave (CHRW) method. This approach, which is based on unitary transformations with a single parameter, treats the rotating and counter-rotating terms on equal footing. In the unitarily transformed representation, we find that it is the multiple-harmonic terms shown in the transformed Hamiltonian that make a crucial contribution to the generation of the exotic plateau phenomenon. By comparing the results of the numerically exact calculation and several other methods, we show that the CHRW results obtained by analytical formalism involving the collective effects of multiple harmonics are in good agreement with the numerical results, which illustrates not only the general tendency of the dynamical evolution of strongly driven TLS, but also the interesting phenomena of plateaus. The developed CHRW method reveals two kinds of plateau patterns: zigzag plateau and armchair plateau, and quantitative analyses are given to comprehensively describe the features of the plateau phenomenon. The plateau phenomenon has a periodical pattern whose frequency is double the driving frequency, and possesses quantized oscillations the number of which has a certain, precise value. Besides, fast oscillation is produced on every plateau which is determined by the relevant driving parameters of the TLS. Our main results are as follows: (i) in the large-amplitude oscillatory case, it turns out that the collective effects of all even harmonics contribute to the generation of zigzag plateau with quantized oscillation, and the general tendency of evolution coincides with the result of the original CHRW method because of a linear trend of the phase function; (ii) in the small-amplitude oscillatory case, the dynamics of the coherent destruction of tunneling under strong driving is exactly exhibited by including the odd-harmonic effect, which offers a novel dynamical pattern, namely, armchair plateau possessing a two-stair structure rather than the complete destruction. Besides, the characteristics of the plateau (position, frequency, the envelope and number of quantized oscillations) are revealed by our analytical formalism. Both of the dynamical patterns are of great interest to strongly driven physics in the ongoing research on driven TLS systems.

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Maximal quantum Fisher information in the semi-classical Rabi model

Cited by 8 publications

References 31 publications

Charging Quantum Batteries with a General Harmonic Driving Field

Charging Quantum Batteries with a General Harmonic Driving Field

Monte Carlo Simulation Method Highlighting on the Electron Beam Irradiation on the Structure of SARS-CoV-2

Plateau dynamics with quantized oscillations of a strongly driven qubit

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