Articles
Publication Date: 2025
Journal of Cosmology and Astroparticle Physics (14757516)2025(5)
In this paper, we develop a quantum field theory framework to describe the interaction between a gravitational wave (GW) background and an electromagnetic (EM) field emitted from a distant celestial source, such as a star. We demonstrate that a background of primordial gravitational waves (PGWs), as predicted by the inflationary scenario, induces a loss of spatial coherence in the EM field as it propagates over cosmological distances. This effect leads to the degradation of van Cittert-Zernike correlations, ultimately rendering them unobservable — a phenomenon referred to as blurring. Since spatial coherence is observed in very long baseline interferometry (VLBI) measurements of distant quasars, this places constraints on the amplitude of the PGW background. We quantitatively evaluate the blurring effect caused by PGWs in a two-mode squeezed state, which represents the standard quantum state predicted by the simplest inflationary models. However, due to the weak coupling between GWs and the EM field, we find that the induced incoherence is too small to be detected in current VLBI observations. © 2025 IOP Publishing Ltd and Sissa Medialab. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
Publication Date: 2024
Physical Review A (24699934)110(1)
Entanglement formation between the magnons as the internal degrees of freedom and the center-of-mass motion (CM) as the external degrees of freedom of a levitated yttrium iron garnet (YIG) sphere in a cavity-magnomechanical system is studied. Here, we propose a scheme for generating magnon-CM entanglement independent from the mass and size of the sphere in the hybrid magnonic system by driving the magnon with the parametric amplification. First, we show that the power and frequency of the driving field significantly affect this entanglement, since the driving field increases effective magnon-CM coupling. But, by increasing the magnon damping rate, this entanglement considerably decreases. Moreover, in the next step, we demonstrate the manipulation and enhancement of this entanglement by driving the magnon into the squeezed state. Our results present an approach for preparing quantum states and may find promising applications in the quantum metrology and sensing. © 2024 American Physical Society.
Publication Date: 2023
Journal of Physics B: Atomic, Molecular and Optical Physics (09534075)56(23)
In this work, we consider a parity-time ( P T ) symmetric cavity magnonic system involving the magnon-photon interaction with small magnon Kerr nonlinearity. Moreover, we investigate the effect of P T -symmetry phase on both the magnon and photon blockade. We show that the P T -symmetry phase, which is achievable by properly selecting the system parameters, can relax the large Kerr nonlinearity requirement for magnon blockade. Consequently, simultaneous perfect magnon and photon blockade can be easily obtained even in the presence of a small value of magnon Kerr nonlinearity. The outstanding feature of the selected scheme is the occurrence of simultaneous perfect magnon and photon blockade with only a small value of magnon Kerr nonlinearity. While photon blockade can be easily distinguished experimentally, the experimental realization of magnon statistics and consequently magnon blockade is still a challenge. The prominent feature of the P T -symmetric cavity magnonic system can relax this challenge by following the magnon blockade criteria via the photon statistics. © 2023 IOP Publishing Ltd.
Publication Date: 2023
Physica Scripta (00318949)98(5)
Based on optical medium analogy, we establish a formalism to describe the interaction between an electromagnetic (EM) system with gravitational waves (GWs) background. After a full discussion on the classical treatment of the EM-GW interaction and finding the EM field mode-functions in the presence of the magneto-dielectric media caused by GWs, the governing quantum interaction Hamiltonian is obtained. Investigation of the optical quadrature variance as well as the visibility of a laser field interacting with the multi-mode squeezed primordial gravitational waves imply that the inflationary primordial gravitational waves (PGWs) act as a decoherence mechanism that destroy EM coherency after a characteristic time scale, τ c , which depends on the inflationary parameters (β, β s , r), or equivalently, the fractional energy density of PGWs, Ω gw,0. The decoherency mechanism overcomes the coherent effects, such as revivals of optical squeezing, thus leaving their confirmation out of reach. Influenced by the continuum of the squeezed PGWs, the laser field suffers a line-width broadening by γ = τ c − 1 . The most peculiar property of the EM spectrum is the apparition of side bands at ω ∼ ω 0 ± 1.39 τ c − 1 Hz, stemming from the squeezed nature of PGWs. The laser phase noise induced by the squeezed PGWs grows with time squarely, Δ ϕ = t / τ c 2 , that can most possibly be sensed within a finite flight time. © 2023 IOP Publishing Ltd
Publication Date: 2023
Materials Chemistry and Physics (02540584)306
Herein, we report the synthesis of a mesoporous calcium silicate superparamagnetic nanoparticle as ZnMnFe2O4@Fe–CaSiO3 core-shell. This core-shell nanocomposite reveals excellent properties such as mesoporous nanocomposite, superparamagnetic at room temperature, low toxicity, large surface area, tunable pore size, and easy surface manipulation. The core nanocomposite (ZnMnFe2O4) is synthesized by the hydrothermal method, which shows a superparamagnetic behavior with an excellent saturation magnetization of 52.09 emu/g. The core-shell structure is prepared by a micellar-assisted sol-gel method, which uses a copolymer to create pores in the structure of CaSiO3. To improve the magnetic properties of the core-shell structure, different percent of Fe ions (0%, 5%, and 10%) are doped onto the calcium silicate structure; as for 10% Fe, i.e., ZnMnFe2O4@Fe10–CaSiO3, saturation magnetization and coercive magnetic field are 34.543 emu/g and 1Oe, respectively. In this configuration of nanocomposite, the pore volume and superparamagnetic property increase simultaneously. In addition, the core-shell mesoporous ZnMnFe2O4@Fe–CaSiO3 nanocomposite reveals comparable mesoporous channels (3.4–6 nm), while the amorphous structure of CaSiO3 has not been changed. These core-shell mesoporous superparamagnetic nanocomposites are evaluated in terms of drug loading and release using epirubicin (EPI) as a model drug. It is found that the increase of iron ions improves the capacity to stabilize the pH environment. Additionally, the mesoporous Fe–CaSiO3 nanostructures demonstrate a sustained drug release property that could be used in local drug delivery therapy. Therefore, these mesoporous superparamagnetic nanostructures would be a promising multifunctional platform for local drug delivery, magnetic resonance imaging, magnetic hyperthermia, and bone tissue regeneration. © 2023 Elsevier B.V.
