arXiv subjects

N. Alessa

Publications and source records attributed to N. Alessa.

3 recordsLinked to original sources

arXiv2025

Squeezing enhanced nonreciprocal quantum correlations via Barnett effect

Cavity optomagnonic platforms offer a promising route for exploring quantum phenomena, particularly quantum correlations, which are vital resources for modern quantum technologies. Here, we propose a theoretical scheme for achieving nonreciprocal quantum correlations such as entanglement, and quantum discord via Barnett effect in a molecular-optomagnonical system, where a yttrium iron garnet sphere is placed in a microwave cavity that is hosting molecules. We show optimal parameter regimes for achieving nonreciprocal quantum correlations through Barnett effect. The generated entanglements are robust against thermal fluctuations, persisting even at high temperatures. Our scheme suggests a new tool for engineering noise-tolerant quantum correlations, and paves a way toward realizing novel nonreciprocal quantum devices by integrating magnons with molecular ensembles.

quant-ph↗

arXiv2025

Dehnen-type dark matter wormholes in the $f(\mathcal{R},\mathcal{L}_m,\mathcal{T})$ action

We are exploring the possibility of traversable wormholes existing in a more realistic context. Specifically, we are looking at scenarios that don't rely on exotic factors, like having a mass shell at the throat or allowing particles and antiparticles to coexist without annihilation. To do this, we are constructing wormholes with double power-law density distributions, drawing inspiration from the Dehnen-type dark matter halo in the framework of generalized geometry-matter coupling gravity. Our investigation carefully considers the challenges of traversability and stability, as well as the roles of exotic matter, the exoticity parameter, and the anisotropy parameter. We have discovered solutions that describe asymmetric, asymptotically flat traversable wormholes, supported by a smooth metric and double power-law density distributions. These solutions successfully avoid the problems, giving us hope that such wormholes could actually exist in nature.

gr-qc↗

arXiv2025

Nonreciprocal entanglement in a molecular optomechanical system

We propose a theoretical scheme to generate nonreciprocal bipartite entanglement between a cavity mode and vibrational modes in a molecular cavity optomechanical system. Our system consists of $\mathcal{N}$ molecules placed inside a spinning whispering-gallery-mode (WGM) resonator. The vibrational modes of these molecules are coupled to the WGM resonator mode (which is analogous to a plasmonic cavity) and the resonator is also coupled to an auxiliary optical cavity. We demonstrate that nonreciprocal photon-vibration entanglement and nonreciprocal vibration-vibration entanglement can be generated in this system, even at high temperatures. These nonreciprocal entanglements arise due to the Sagnac-Fizeau effect induced by the spinning WGM resonator. We find that spinning the WGM resonator in the counter-clockwise (CCW) direction enhances both types of nonreciprocal entanglement, especially under blue-detuned driving of the optical cavity mode. Furthermore, we show that vibration-vibration entanglement can be significantly enhanced by increasing the number of molecules. Our findings have potential applications in quantum information transmission and in the development of nonreciprocal quantum devices.

quant-ph↗