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We show that a quantum subsystem can become significantly entangled with a classical background through a process with little or none semi-classical back-reactions. We study two quantum harmonic oscillators coupled to each other in a…

High Energy Physics - Theory · Physics 2017-07-19 I-Sheng Yang

In their activity, the traders approximate the rate of return by integer multiples of a minimal one. Therefore, it can be regarded as a quantized variable. On the other hand, there is the impossibility of observing the rate of return and…

General Finance · Quantitative Finance 2014-12-12 Liviu-Adrian Cotfas

We present the general solutions for the classical and quantum dynamics of the anharmonic oscillator coupled to a purely diffusive environment. In both cases, these solutions are obtained by the application of the Baker-Campbell-Hausdorff…

Quantum Physics · Physics 2007-06-07 J. G. Peixoto de Faria

As part of a probabilistic reconstruction of quantum theory (QT), we show that spin is not a purely quantum mechanical phenomenon, as has long been assumed. Rather, this phenomenon occurs before the transition to QT takes place, namely in…

Quantum Physics · Physics 2025-02-18 Ulf Klein

Several approaches to quantum gravity lead to nonlocal modifications of fields' dynamics. This, in turn, can give rise to nonlocal modifications of quantum mechanics at non-relativistic energies. Here, we analyze the nonlocal…

General Relativity and Quantum Cosmology · Physics 2024-09-17 Marzena Ciszak , Alessio Belenchia , Antonello Ortolan , Francesco Marino

The nature of time in quantum mechanics is closely related to the use of a complex, rather than say real, Hilbert space. This becomes particularly clear when considering quantum field theory in time dependent backgrounds, such as in…

General Relativity and Quantum Cosmology · Physics 2011-11-03 G. W. Gibbons

Utilizing the program of expectation values in coherent states and its recently developed algorithmic tools, this letter investigates the dynamical properties of cosmological coherent states for Loop Quantum Gravity. To this end, the…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Klaus Liegener , Łukasz Rudnicki

The conventional view, that Einstein was wrong to believe that quantum physics is local and deterministic, is challenged. A parametrised model, Q, for the state vector evolution of spin 1/2 particles during measurement is developed. Q draws…

Quantum Physics · Physics 2008-02-03 T. N. Palmer

We consider the quantum evolution of classically chaotic systems in contact with surroundings. Based on $\hbar$-scaling of an equation for time evolution of the Wigner's quasi-probability distribution function in presence of dissipation and…

chao-dyn · Physics 2015-06-24 B. C. Bag , S. Chaudhuri , J. Ray Chaudhuri , D. S. Ray

We give a simple demonstration that the Schr\"odinger equation may be recast as a self-contained second-order Newtonian law for a congruence of spacetime trajectories. This provides a pictorial representation of the quantum state as the…

Quantum Physics · Physics 2018-08-23 Peter Holland

We use spin coherent states to compare classical and quantum evolution of a simple paradigmatic, discrete-time quantum dynamical system exhibiting chaotic behavior in the classical limit. The spin coherent states are employed to define a…

Quantum Physics · Physics 2020-10-29 Marek Kuś , Robert Przybycień

We investigate a quantum algorithm which simulates efficiently the quantum kicked rotator model, a system which displays rich physical properties, and enables to study problems of quantum chaos, atomic physics and localization of electrons…

Quantum Physics · Physics 2007-05-23 B. Levi , B. Georgeot , D. L. Shepelyansky

We study the dynamics of a "kicked" quantum system undergoing repeated measurements of momentum. A diffusive behavior is obtained for a large class of Hamiltonians, even when the dynamics of the classical counterpart is not chaotic. These…

Quantum Physics · Physics 2007-05-23 P. Facchi , S. Pascazio , A. Scardicchio

We develop a novel approach to Quantum Mechanics that we call Curved Quantum Mechanics. We introduce an infinite-dimensional K\"ahler manifold ${\cal M}$, that we call the state manifold, such that the cotangent space $T_z^*{\cal M}$ is a…

Quantum Physics · Physics 2024-12-12 Ivan G. Avramidi , Roberto Niardi

In spin systems, the decay of the Loschmidt echo in the time-reversal experiment (evolution, perturbation, time-reversed evolution) is linked to the generation of multiple-quantum coherences. The approach is extended to other systems, and…

Quantum Physics · Physics 2015-11-11 A. K. Khitrin

In quantum mechanics courses, students often solve the Schr\"odinger equation for the harmonic oscillator with time-independent parameters. However, time-dependent quantum harmonic oscillators are relevant in modeling several problems as,…

Quantum Physics · Physics 2025-06-12 Stanley S. Coelho , Lucas Queiroz , Danilo T. Alves

In classical mechanics, a light particle bound by a strong elastic force just oscillates at high frequency in the region allowed by its initial position and velocity. In quantum mechanics, instead, the ground state of the particle becomes…

General Physics · Physics 2017-01-03 G. Modanese

There is a property of a quantum state called magic. It measures how difficult for a classical computer to simulate the state. In this paper, we study magic of states in the integrable and chaotic regimes of the higher-spin generalization…

High Energy Physics - Theory · Physics 2021-12-30 Kanato Goto , Tomoki Nosaka , Masahiro Nozaki

In a previous paper [J.S.Briggs and A.Eisfeld, Phys.Rev.A 85, 052111] we showed that the time-development of the complex amplitudes of N coupled quantum states can be mapped by the time development of positions and velocities of N coupled…

Quantum Physics · Physics 2014-02-18 J. S. Briggs , A. Eisfeld

Using the remarkable mathematical construct of Eugene Wigner to visualize quantum trajectories in phase space, quantum processes can be described in terms of a quasi-probability distribution analogous to the phase space probability…

Quantum Physics · Physics 2013-01-29 Frank Kirtschig , Jorrit Rijnbeek , Jeroen van den Brink , Carmine Ortix