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Georgi Gary Rozenman

Publications and source records attributed to Georgi Gary Rozenman.

9 recordsLinked to original sources

Phase Dynamics of Self-Accelerating Bose-Einstein Condensates

Self-accelerating Airy matter waves offer a clean setting to access the intrinsic cubic-in-time phase. Here we reconstruct the relative phase of simulated Airy-shaped Bose-Einstein condensates from interference fringes in free space, a regime approached in microgravity. The cubic phase dynamics are quantified via approximately debiased, windowed polynomial fits with systematics-aware uncertainty estimates that account for window-induced correlations. We compare two physically feasible phase-extraction methods, heterodyne-based and density-based, and show that an Airy-Gaussian geometry yields substantially improved robustness to fit-window selection relative to an Airy-Airy collision. In the weakly interacting regime, the extracted cubic coefficient responds linearly to leading order to the effective interaction strength, its shift from the noninteracting value providing a calibrated probe of weak mean-field nonlinearities in self-accelerating condensates.

cond-mat.quant-gas↗

Theory of Cubic-Phase Dynamics in the Linear Potential

A quantum wave packet in a linear potential, i.e., under a constant force such as gravity, accumulates a cubic-in-time phase that is universal across Schrodinger-type platforms and naturally realized by Airy eigenstates. Because the classical action is quadratic in the force, this phase comprises exactly three contributions: intrinsic, force-induced, and a cross term. The force-induced contribution alone is shape-independent, whereas the Airy eigenstate renders the shape-dependent contributions non-dispersing. An eigenstate-based nondimensionalization identifies the eigenforce, namely the intrinsic force underlying the packet's acceleration in the absence of an applied force, as a natural parameter. As a function of both forces, the cubic coefficient takes an analytically closed and physically interpretable form that factors along two zero lines: the static Airy eigenstate and a nontrivial zero at which the phase cancels without stationarity. This exposes the eigenforce as an effective antagonist to the applied force, not only in the caustic's self-acceleration but also within the phase, while leaving the centroid unaffected in accordance with Ehrenfest's theorem. Spatially uniform within each packet, the phase cannot be measured directly and is accessible only through the relative phase of two colliding packets, each evolving in its own potential. The general relative cubic coefficient, forbidden by symmetry for identical packets and activated by preparation asymmetry, therefore provides a designable signal. Extracted through heterodyne demodulation of the simulated interference between two Airy packets, its central value agrees with the prediction to sub-percent accuracy within the fitting uncertainty. The analysis spans ultracold-atom condensates, paraxial optics, and surface-gravity water waves.

quant-ph↗

Observation of Phase Space Dynamics of Inverted Harmonic Oscillator

We have experimentally realized a parabolic potential barrier for surface gravity water waves. The analogy between the resulting wave equation and the Schrodinger equation for the inverted harmonic oscillator (IHO) enables us to study the propagation of quantum-mechanical wave packets with different average energies in this iconic scattering model. We observe a clear boundary in the phase-space dynamics, namely the separatrix, which distinguishes wave packets with energies below the maximum of the IHO potential from those with energies above it. In the former case, the wave packet is blocked, whereas in the latter case, it is transmitted. We also measure the corresponding variation in momentum during this process.

physics.class-ph↗

Engineering classical waves with quantized energy spectra in periodic media

Field quantization is a central feature of modern physics, that underpins the concept of photons and forms the foundation of quantum electrodynamics as well as much of solid-state theory. Classical linear wave equations are not generally expected to reproduce the quantization arising in quantum systems without introducing additional ingredients such as ad hoc nonlinear constraints, resonant particle-wave couplings or stochastic background fields. Here, we show that appropriately engineered linear wave media can recover fundamental features evocative of energy quantization in quantum mechanics. The key is to tailor periodic media in which wave propagation is strongly suppressed, except over a discrete set of narrow pass bands. In this regime, stationary wave solutions exhibit discrete energy and frequency spectra analogous to those arising in quantum mechanics despite the underlying dynamics remaining linear. Owing to the universality of the proposed mechanism, these effects may be realized experimentally using mechanical, electrical, or electromagnetic waves in appropriately designed periodic media. This work opens new avenues for designing metamaterials that enable control over discrete wave states while strengthening the conceptual bridge between classical and quantum wave physics.

math-ph↗

Free-space and Satellite-Based Quantum Communication: Principles, Implementations, and Challenges

Satellite-based quantum communications represent a critical advancement in the pursuit of secure, global-scale quantum networks. Leveraging the principles of quantum mechanics, these systems offer unparalleled security through Quantum Key Distribution (QKD) and other quantum communication protocols. This review provides a comprehensive overview of the current state of satellite-based quantum communications, focusing on the evolution from terrestrial to space-based systems. We explore the distinct advantages and challenges of discrete-variable (DV) and continuous-variable (CV) quantum communication technologies in the context of satellite deployments. The paper also discusses key milestones such as the successful implementation of quantum communication via the Micius satellite and outlines the primary challenges, including atmospheric turbulence and the development of quantum repeaters, that must be addressed to achieve a global quantum internet. This review aims to consolidate recent advancements in the field, providing insights and perspectives on the future directions and potential innovations that will drive the continued evolution of satellite-based quantum communications.

quant-ph↗

Observation of the Aharonov-Bohm Effect in Pilot-Wave Hydrodynamics

We report the results of an experimental study of an analog of the Aharonov-Bohm (AB) effect achieved with the hydrodynamic pilot-wave system. A walking droplet is confined to an annular cavity that encircles a shielded vortex, but lies outside its range of direct influence. While there is no vortex-induced flow in the immediate vicinity of the droplets, the vortex modifies the droplet's spatially extended pilot-wave field that guides its motion, producing a vortex-dependent bias in the droplet's orbital speed. High-speed tracking and delay-embedding reconstructions yield Wigner-like phase-space distributions for this hydrodynamic system that exhibits a rigid, flux-dependent translation, providing a force-free, gauge-like realization of an AB-type phase.

physics.flu-dyn↗

Emulation of the Six-State Quantum Key Distribution Protocol with Pulsed Lasers

Quantum cryptography remains a topic of enduring scientific and educational interest. Here, we present a clear and accessible framework for exploring the six-state quantum key distribution protocol, an enhanced three-basis extension of the BB84 scheme that combines optical experiments with computational analysis. Designed for testing quantum communication protocols through emulation, this approach provides a robust and cost-effective platform that highlights the fundamental principles of multi-basis encoding and demonstrates how experimental measurements connect directly to theoretical expectations in a controlled tabletop setting.

quant-ph↗

Diffractive Guiding of Waves by a Periodic Array of Slits

We show that in order to guide waves, it is sufficient to periodically truncate their edges. The modes supported by this type of wave guide propagate freely between the slits, and the propagation pattern repeats itself. We experimentally demonstrate this general wave phenomenon for two types of waves: (i) plasmonic waves propagating on a metal-air interface that are periodically blocked by nanometric metallic walls, and (ii) surface gravity water waves whose evolution is recorded, the packet is truncated, and generated again to show repeated patterns. This guiding concept is applicable for a wide variety of waves.

physics.optics↗

Projectile motion of surface gravity water wave packets: An analogy to quantum mechanics

We study phase contributions of wave functions that occur in the evolution of Gaussian surface gravity water wave packets with nonzero initial momenta propagating in the presence and absence of an effective external linear potential. Our approach takes advantage of the fact that in contrast to matter waves, water waves allow us to measure both their amplitudes and phases.

quant-ph↗