scholarly journals Tomographic Description of a Quantum Wave Packet in an Accelerated Frame

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 636
Author(s):  
Sergio De Nicola ◽  
Renato Fedele ◽  
Dušan Jovanovic ◽  
Margarita Man'ko ◽  
Vladimir Man'ko
Keyword(s):  
Wave Packet ◽  
Force Field ◽  
Inertial Frame ◽  
Free Motion ◽  
Gaussian State ◽  
Spatiotemporal Evolution ◽  
Uncertainty Product ◽  
State Evolution ◽  
Quantum Wave ◽  
Arbitrary Time Dependence

The tomography of a single quantum particle (i.e., a quantum wave packet) in an accelerated frame is studied. We write the Schrödinger equation in a moving reference frame in which acceleration is uniform in space and an arbitrary function of time. Then, we reduce such a problem to the study of spatiotemporal evolution of the wave packet in an inertial frame in the presence of a homogeneous force field but with an arbitrary time dependence. We demonstrate the existence of a Gaussian wave packet solution, for which the position and momentum uncertainties are unaffected by the uniform force field. This implies that, similar to in the case of a force-free motion, the uncertainty product is unaffected by acceleration. In addition, according to the Ehrenfest theorem, the wave packet centroid moves according to classic Newton's law of a particle experiencing the effects of uniform acceleration. Furthermore, as in free motion, the wave packet exhibits a diffraction spread in the configuration space but not in momentum space. Then, using Radon transform, we determine the quantum tomogram of the Gaussian state evolution in the accelerated frame. Finally, we characterize the wave packet evolution in the accelerated frame in terms of optical and simplectic tomogram evolution in the related tomographic space.

GEOMETRIC PHASES, SQUEEZED QUANTUM STATES AND GAUSSIAN WAVE PACKET STATES OF RELIC GRAVITONS

2012 ◽  
Vol 18 ◽  
pp. 13-17
Author(s):  
K. BAKKE ◽  
I. A. PEDROSA ◽  
C. FURTADO
Keyword(s):  
Wave Packet ◽  
Linear Time ◽  
Invariant Operator ◽  
Quantum States ◽  
Time Dependent ◽  
Gaussian Wave Packet ◽  
Geometric Phases ◽  
Uncertainty Product ◽  
Quantized Field ◽  
Generalized Time

In this contribution, we discuss quantum effects on relic gravitons described by the Friedmann-Robertson-Walker (FRW) spacetime background by reducing the problem to that of a generalized time-dependent harmonic oscillator, and find the corresponding Schrödinger states with the help of the dynamical invariant method. Then, by considering a quadratic time-dependent invariant operator, we show that we can obtain the geometric phases and squeezed quantum states for this system. Furthermore, we also show that we can construct Gaussian wave packet states by considering a linear time-dependent invariant operator. In both cases, we also discuss the uncertainty product for each mode of the quantized field.

scholarly journals Time-covariant Schrödinger equation and invariant decay probability: the $$\Lambda $$-Kantowski–Sachs universe

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Theodoros Pailas ◽  
Nikolaos Dimakis ◽  
Petros A. Terzis ◽  
Theodosios Christodoulakis
Keyword(s):  
Schrödinger Equation ◽  
Wave Packet ◽  
Time Dependence ◽  
Schrodinger Equation ◽  
Canonical Quantization ◽  
Dynamical Equations ◽  
Quadratic Constraint ◽  
Decay Probability ◽  
Flrw Universe ◽  
Arbitrary Time Dependence

AbstractThe system under study is the $$\Lambda $$ Λ -Kantowski–Sachs universe. Its canonical quantization is provided based on a recently developed method: the singular minisuperspace Lagrangian describing the system, is reduced to a regular (by inserting into the dynamical equations the lapse dictated by the quadratic constraint) possessing an explicit (though arbitrary) time dependence; thus a time-covariant Schrödinger equation arises. Additionally, an invariant (under transformations $$t=f({\tilde{t}})$$ t = f ( t ~ ) ) decay probability is defined and thus “observers” which correspond to different gauge choices obtain, by default, the same results. The time of decay for a Gaussian wave packet localized around the point $$a=0$$ a = 0 (where a the radial scale factor) is calculated to be of the order $$\sim 10^{-42}{-}10^{-41}~\text {s}$$ ∼ 10 - 42 - 10 - 41 s . The acquired value is near the end of the Planck era (when comparing to a FLRW universe), during which the quantum effects are most prominent. Some of the results are compared to those obtained by following the well known canonical quantization of cosmological systems, i.e. the solutions of the Wheeler–DeWitt equation.

scholarly journals Numerical Study of Quantum Wave Packet in Meshless Particle Method

2019 ◽  
Vol 18 (3) ◽  
pp. 159-161 ◽  
Author(s):  
Fumiaki HIRONO ◽  
Misako IWASAWA ◽  
Satoru S. KANO ◽  
Yasunari ZEMPO
Keyword(s):  
Wave Packet ◽  
Numerical Study ◽  
Particle Method ◽  
Quantum Wave ◽  
Meshless Particle Method

Theoretical investigations of the Au++H2 reactive scattering by the time-dependent quantum wave packet method

2017 ◽  
Vol 31 (06) ◽  
pp. 1750039 ◽  
Author(s):  
Wentao Lee ◽  
Haixiang He ◽  
Maodu Chen
Keyword(s):  
Wave Packet ◽  
Cross Sections ◽  
Collision Energy ◽  
Time Dependent ◽  
Reactive Scattering ◽  
Total Reaction ◽  
Theoretical Investigations ◽  
Classical Trajectories ◽  
Quantum Wave

Employing the state-to-state time-dependent quantum wave packet method, the Au[Formula: see text]H2 reactive scattering with initial states [Formula: see text], [Formula: see text] and 1 were investigated. Total reaction probabilities, product state-resolved integral cross-sections (ICSs) and differential cross-sections (DCSs) were calculated up to collision energy of 4.5 eV. The numerical results show that total reaction probabilities and ICSs increase with increasing collision energies, and there is little effect to the reactive scattering processes from the rotational excitation of H2 molecule. Below collision energy of around 3.0 eV, the role of the potential well in the entrance channel is significant and the reactive scattering proceeds dominantly by an indirect process, which leads to a nearly symmetric shape of the DCSs. With collision energy higher than 4.0 eV, the reactive scattering proceeds through a direct process, which leads to a forward biased DCSs, and also a hotter rotational distributions of the products. Total ICS agrees with the results by the quasi-classical trajectories theory very well, which suggests that the quantum effects in this reactive process are not obvious. However, the agreement between the experimental total cross-section and our theoretical result is not so good. This may be due to the uncertainty of the experiment or/and the inaccuracy of the potential energy surface.

Quantum wave packet study of Li+H2+ inelastic scattering

2005 ◽  
Vol 407 (4-6) ◽  
pp. 298-302 ◽  
Author(s):  
Niyazi Bulut ◽  
Fahrettin Gogtas ◽  
Sinan Akpinar
Keyword(s):  
Wave Packet ◽  
Inelastic Scattering ◽  
Quantum Wave
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