arXiv subjects

Varqa Abyaneh

Publications and source records attributed to Varqa Abyaneh.

4 recordsLinked to original sources

arXiv2024

Iterative Confinement of Ions via the Quantum Zeno Effect: Probing Paradoxical Energy Consequences

Building upon our previously introduced mechanism for ion trapping based on the quantum Zeno effect (QZE), we propose a novel approach to systematically draw ions closer together, solely via quantum measurements. The proposed method involves repeated measurements of the electromagnetic force exerted by ions on an enclosure of conductor plates to confine the ions within an incrementally smaller spatial region, achieved by exploiting the behaviour of the wavefunction at its boundaries. Taking a two-proton system as a case study, we explore the dynamics between the energy gain of the system, attributed to successive QZE measurements, and the energy expended making such measurements. The results reveal a paradox wherein, under specific circumstances, protons appear to accumulate more energy than is seemingly introduced into the system. This peculiarity aligns with prior studies that highlight challenges in energy conservation within quantum mechanics. To verify these observations, we propose an iterative confinement setup that is feasible with current technological capabilities. Confirmation of these findings could offer new insights for applications in quantum physics, including fusion research. Therefore, the proposed novel method of manipulating ions not only harbours considerable potential for diverse applications but also furnishes an additional tool for probing fundamental questions in the field.

quant-ph↗

arXiv2024

Quantum Zeno Dynamics of Two Interacting Particles

According to quantum Zeno dynamics (QZD), the evolution of a quantum system can be restricted to a subspace of its Hilbert space by frequent measurements. A crucial question in QZD of a particle's position is: how short the time interval between successive measurements should be, in order to confine the particle in its initial spatial region? To address this question, we consider a toy model with two ions initially known to be, for simplicity, in a one-dimensional spatial region. By simulating the evolution of this two-body quantum system, we estimate the measurement frequency needed to keep the ions within their initial confined region at a desired confidence level. Two key parameters we employ in our calculations are the Zeno time and the leakage probability of the quantum system. The measurement frequencies are calculated and compared when ions are located initially at different spatial regions. For our simulation, we introduce the Python code {\tt 2IonQZD}.

quant-ph↗

arXiv2007

Expectation values, experimental predictions, events and entropy in quantum gravitationally decohered quantum mechanics

We restate Kay's 1998 hypothesis which simultaneously offers an objective definition for the entropy of a closed system, a microscopic foundation for the Second Law, a resolution of the Information Loss (and other) Black-Hole Puzzle(s) and an objective mechanism for decoherence. Presupposing a conventional unitary theory of low-energy quantum gravity, it offers all this by taking the physical density operator of a closed system to be the partial trace of its total density operator (assumed pure) over gravity and by defining its physical entropy to be its `matter-gravity entanglement entropy'. We also recall Kay's 1998 modified non-relativistic (many-body) quantum mechanics based on Kay's hypothesis with a Newtonian approximation to quantum gravity. In this modification, we find formal expectation values for certain `observables' such as momentum-squared and Parity are altered but those for functions of positions are unaltered. However, by arguing that every real measurement can ultimately be taken to be a position measurement, we prove that, in practice, it is impossible to detect any alteration at all and, in particular, we predict no alteration for Roger Penrose's experiment. Nevertheless, Kay's modification contains no Schrödinger Cat-like states, and also allows an `events' interpretation which we tentatively propose and begin to explore. We also obtain a Second-Law type result for a non-relativistic toy-model closed system and argue that similar results will apply for a wide class of model Newtonian and post-Newtonian closed systems although we argue that ordinary actual lab-sized systems can never be treated as closed for the purpose of calculating their entropy. Compared with `collapse models' such as GRW, Kay's Newtonian theory does a similar job while being free from ad hoc assumptions.

quant-ph↗

arXiv2006

The robustness of a many-body decoherence formula of Kay under changes in graininess and shape of the bodies

In ``Decoherence of macroscopic closed systems within Newtonian quantum gravity'' (Kay B S 1998 Class. Quantum Grav. 15 L89-L98) it was argued that, given a many-body Schroedinger wave function ψ(x_1,...,x_N) for the centre-of-mass degrees of freedom of a closed system of N identical uniform-mass balls of mass M and radius R, taking account of quantum gravitational effects and then tracing over the gravitational field amounts to multiplying the position-space density matrix ρ(x_1,...,x_N; x_1',...,x_N')= ψ(x_1,...,x_N)ψ*(x_1',...,x_N') by a multiplicative factor, which, if the positions {x_1,...,x_N; x_1',...,x_N'} are all much further away from one another than R, is well-approximated by the product from 1 to N over I, J, K (I 0) of radius r with centres at the vertices of a cubic lattice of spacing a (assumed to be very much bigger than 2r) and side 2La we establish the bound e^{-1/3}(r/a)^{1/n}La < R_eff < 2\sqrt 3(r/a)^{1/n} La.

gr-qc↗