Dissipation and decoherence effects on a moving particle in front of a dielectric plate

Farías, M. Belén; Lombardo, Fernando C.

doi:10.1103/physrevd.93.065035

Cited by 17 publications

(25 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As it has been considered previously in the Literature [31], the internal degree of freedom of the particle interacts with the vacuum field through a given current j(x). The interaction term can then be written as S…”

mentioning

confidence: 99%

“…Recently, in Ref. [31], the decoherence process on the internal degree of freedom of a moving particle with constant velocity (parallel to a dielectric mirror) has been studied. The loss of quantum coherence of the particle's dipolar moment becomes relevant in any interferometry experiment, where the depolarisation of the atom could be macroscopically observed by means of the Ramsey fringes [32,33].…”

mentioning

confidence: 99%

“…In [31] it has been derived the in-out effective action for the particle, which is the action obtained after functionally integrating over the vacuum field and over the internal degrees of freedom of the dielectric plate (polarisation degrees of freedom) ψ(x). The reason to evaluate the in-out effective action is that this is related to the vacuum persistence amplitude, and the presence of an imaginary part signals the excitation of internal degrees of freedom on the mirror.…”

mentioning

confidence: 99%

“…Despite this freedom from complexity, the model admits the calculation of some relevant quantities without much further assumptions. In order to consider how the relative motion between the particle and the plate affects the geometric phase acquired we shall follow the procedure presented in previous works [31,34].…”

mentioning

confidence: 99%

See 3 more Smart Citations

Geometric phase corrections on a moving particle in front of a dielectric mirror

Lombardo¹,

Villar²

2017

EPL

Self Cite

View full text Add to dashboard Cite

-We consider an atom (represented by a two-level system) moving in front of a dielectric plate, and study how traces of dissipation and decoherence (both effects induced by vacuum field fluctuations) can be found in the corrections to the unitary geometric phase accumulated by the atom. We consider the particle to follow a classical, macroscopically-fixed trajectory and integrate over the vacuum field and the microscopic degrees of freedom of both the plate and the particle in order to calculate friction effects. We compute analytically and numerically the non-unitary geometric phase for the moving qubit under the presence of the quantum vacuum field and the dielectric mirror. We find a velocity dependence in the correction to the unitary geometric phase due to quantum frictional effects. We also show in which cases decoherence effects could, in principle, be controlled in order to perform a measurement of the geometric phase using standard procedures as Ramsey-like interferometry.Introduction. -A system can retain the information of its motion when it undergoes a cyclic evolution in the form of a geometric phase, which was first put forward by Pancharatman in optics [1] and later studied explicitly by Berry in a general quantal system [2]. Since the work of Berry, the notion of geometric phases has been shown to have important consequences for quantum systems. Berry demonstrated that quantum systems could acquire phases that are geometric in nature. He showed that, besides the usual dynamical phase, an additional phase related to the geometry of the space state is generated during an adiabatic evolution. Since then, great progress has been achieved in this field. Due to its global properties, the geometric phase is propitious to construct fault tolerant quantum gates. In this line of work, many physical systems have been investigated to realise geometric quantum computation, such as NMR (Nuclear Magnetic Resonance) [3], Josephson junction [4], Ion trap [5] and semiconductor quantum dots [6]. The quantum computation scheme for the geometric phase has been proposed based on the Abelian or non-Abelian geometric concepts, and the geometric phase has been shown to be robust against faults in the presence of some kind of external noise due to the geometric nature of Berry phase [7][8][9]. It was therefore seen that interactions play an important role in the realisation of some specific operations. As the gates operate

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Geometric phase corrections on a moving particle in front of a dielectric mirror

Lombardo¹,

Villar²

2017

EPL

Self Cite

View full text Add to dashboard Cite

show abstract

“…Finally, the diffraction spectra are being computed using both classical and quantum dynamics simulations. Although diffraction is a 'pure' quantum phenomenon and quantum dynamics is, in principle, unavoidable to study our system, a classical analysis based on parallel momentum binning [3] has already been revealed as a very useful tool to mimic and analyze diffraction spectra [4,5]. Figure 1.…”

Section: Synopsismentioning

confidence: 99%

Theoretical study of noble gases diffraction from Ru(0001) using van der Waals DFT-based potentials

Cueto

Muzas

Martín

et al. 2015

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

A Magnus approximation approach to harmonic systems with time-dependent frequencies

2018

View full text Add to dashboard Cite

We use a Magnus approximation at the level of the equations of motion for a harmonic system with a time-dependent frequency, to find an expansion for its in-out effective action, and a unitary expansion for the Bogoliubov transformation between in and out states. The dissipative effects derived therefrom are compared with the ones obtained from perturbation theory in powers of the time-dependent piece in the frequency, and with those derived using multiple scale analysis in systems with parametric resonance. We also apply the Magnus expansion to the in-in effective action, to construct reality and causal equations of motion for the external system. We show that the nonlocal equations of motion can be written in terms of a "retarded Fourier transform" evaluated at the resonant frequency. observable, namely, the dynamical equations for the external degrees of freedom. They may be obtained from the in-in effective action, and exhibit a back-reaction due to emission of quantum field modes [5,6].Except for rather special cases, it is not possible to obtain closed expressions for the effective action, even in the case of a single harmonic mode with a time-dependent frequency. Indeed, the problem of evaluating the effective action for a system like this, may be posed in terms of a functional determinant, an object which may be obtained from the solution of a linear secondorder differential equation: the classical equation of motion. Since, except for rather special cases, closed solutions for the latter are not known, it is natural to implement approximate treatments. Assuming that the time dependent piece of the frequency is small in comparison with the constant (average) part, an expansion in powers of the former seems natural. The alternative we follow here, corresponds to writing the (formal) solution to the classical equation of motion in phase space, and implementing the Magnus expansion [7,8,9] to solve the latter. This preserves, order by order, the time evolution as a canonical transformation, both at the classical and quantum levels (since the equations of motion are linear). This is a higher desirable feature when considering an expansion for the Bogoliubov transformations, Thus, our approach may be interpreted as an alternative expansion in the time-dependent part of the frequency, which preserves unitarity, and would correspond to a resummation of infinite terms on the usual expansion.The Magnus approach has been used in a large number of works and is of interest in many branches of quantum mechanics. For example, it han been used in the open quantum systems theory as a tool to investigate how to manipulate the irreversible component of open-system evolutions (decoherence and dissipation) through the application of external controllable interactions [10]. Also in the study of periodically driven systems, by means of an expansion both in the driving term and the inverse of the driving frequency, applicable to isolated or dissipative systems. In [11], a systematic Magnus expansion is used to derive explicit e...

show abstract

Dissipation and decoherence effects on a moving particle in front of a dielectric plate

Cited by 17 publications

References 36 publications

Geometric phase corrections on a moving particle in front of a dielectric mirror

Geometric phase corrections on a moving particle in front of a dielectric mirror

Theoretical study of noble gases diffraction from Ru(0001) using van der Waals DFT-based potentials

A Magnus approximation approach to harmonic systems with time-dependent frequencies

Contact Info

Product

Resources

About