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Mohammad Sharifian

Publications and source records attributed to Mohammad Sharifian.

7 recordsLinked to original sources

Hybrid Boson Sampling-Neural Network Architecture for Enhanced Classification

Demonstration of quantum advantage for classical machine learning tasks remains a central goal for quantum technologies and artificial intelligence. Two major bottlenecks to this goal are the high dimensionality of practical datasets and limited performance of near-term quantum computers. Boson sampling is among the few models with experimentally verified quantum advantage, yet it lacks practical applications. Here, we develop a hybrid framework that combines the computational power of boson sampling with the adaptability of neural networks to construct quantum kernels that enhance support vector machine classification. The neural network adaptively compresses the data features onto a programmable boson sampling circuit, producing quantum states that span a high-dimensional Hilbert space and enable improved classification performance. Using four datasets with various classes, we demonstrate that our model outperforms classical linear and sigmoid kernels. These results highlight the potential of boson sampling-based quantum kernels for practical quantum-enhanced machine learning.

quant-ph

Exploring gravitational impulse via quantum Boltzmann equation

We investigate the gravitational impulse by using the generalized formulation of the quantum Boltzmann equation (QBE), wherein the initial states are taken as wave packets rather than plane waves. The QBE operates within an open quantum system framework. Using this approach, we can analyze the two-body gravitational scattering by considering one body as part of the environment and the other as the system. Through this procedure, we obtain the system's impulse up to the second order for two massive objects. Similarly, we apply the forward scattering of the QBE to the gravitational impulse of a photon due to a massive object, during which we consider the photon as the system and the massive object as the environment. In this methodology, we use the QBE to compute the time evolution of the momentum operator associated with the system. While the forward scattering term vanishes when considering point particles, we demonstrate its persistence when using wave packets to describe both massive particles and the photon field. The results reported here are entirely consistent with the previous approaches.

gr-qc

Induced Circular Polarization on Photons Due to Interaction with Axion-Like Particles in Rotating Magnetic Field of Neutron Stars

We investigate how the photon polarization is affected by the interaction with axion-like particles (ALPs) in the rotating magnetic field of a neutron star (NS). Using quantum Boltzmann equations the study demonstrates that the periodic magnetic field of millisecond NSs enhances the interaction of photons with ALPs and creates a circular polarization on them. A binary system including an NS and a companion star could serve as a probe. When the NS is in front of the companion star with respect to the earth observer, there is a circular polarization on the previously linearly polarized photons as a result of the interaction with ALPs there. After a half-binary period, the companion star passes in front of the NS, and the circular polarization of photons disappears and changes to linear. The excluded parameter space for a millisecond NS with 300~Hz rotating frequency, highlights the coupling constant of $1.7\times10^{-11}~\text{GeV}^{-1}\leq g_{aγγ}\leq1.6\times10^{-3}~\text{GeV}^{-1}$ for the ALP masses in the range of $7\times10^{-12}~\text{eV}\leq m_a\leq1.5\times 10^{3}~\text{eV}$.

astro-ph.HE

Open Quantum System Approach to the Gravitational Decoherence of Spin-1/2 Particles

This paper investigates the decoherence effect resulting from the interaction of squeezed gravitational waves with a system of massive particles in spatial superposition. This paper investigates the decoherence effect resulting from the interaction of squeezed gravitational waves with a system of massive particles in spatial superposition. We first employ the open quantum system approach to obtain the established decoherence in a spatial superposition of massive objects induced by squeezed gravitational waves. Subsequently, we focus on the spin-1/2 particle system, and our analysis reveals that the decoherence rate depends on both the squeezing strength and the squeezing angle of the gravitational waves. Our results demonstrate that squeezed gravitational waves with squeezing strengths of $r_p\geq1.2$ and a squeezing angle of $φ_p=π/2$ can induce a 1 % decoherence within 1 s free falling of a cloud of spin-1/2 particles. This investigation sheds light on the relationship between squeezed gravitational waves and the coherence of spatial superposition states in systems of massive particles and their spin. The dependence of decoherence on squeezing strength and, in the case of spin-$1/2$ particles, on the squeezing angle paves the way for further exploration and understanding of the quantum-gravity connection. We suggest that such an experimental setup could also be employed to eventually investigate the level of squeezing effect (and hence quantum-related properties) of gravitational waves produced in the early universe from inflation.

gr-qc

Probing Virtual ALPs by Precision Phase Measurements: Time-Varying Magnetic Field Background

We propose an experimental scheme for detecting the effects of off-shell axion-like particles (ALPs) through optical cavities. In this proposed experiment, linearly polarized photons are pumped into an optical cavity where an external time-dependent magnetic field is present. The magnetic field mediates an interaction between the cavity photons and ALPs giving rise to a modification in the phase of the cavity photons. The time-dependent nature of the external magnetic field prompts a novel amplification effect which significantly enhances this phase modification. A detection scheme is then proposed to identify such axion-induced phase shifts. We find that the phase modification is considerably sensitive to the photon-ALPs coupling constants $g_{aγγ}$ for the range of ALPs mass $3.1\:μ\textrm{eV}\leqslant m_a \leqslant 44.4\:μ\textrm{eV}$.

hep-ph

Axion-Like Dark Matter Detection Using Stern-Gerlach Interferometer

Quantum sensors based on the superposition of neutral atoms are promising for sensing the nature of dark matter (DM). In this study, we utilize the Stern-Gerlach (SG) interferometer configuration to seek a novel method for the detection of detect axion-like particles (ALPs). Using an SG interferometer, we create a spatial quantum superposition of neutral atoms such as $^{3}$He and $^{87}$Rb. It is shown that the interaction of ALPs with this superposition induces a relative phase between superposed quantum components. We use the quantum Boltzmann equation (QBE) to introduce a first-principles analysis that describes the temporal evolution of the sensing system. The QBE approach employs quantum field theory (QFT) to highlight the role of the quantum nature of the interactions with the quantum systems. The resulting exclusion area demonstrates that our scheme allows for the exclusion of a range of ALP mass in the range of $10^{-10}\leq m_{a}\leq 10^{2}\,\mathrm{eV}$ and ALP-atom coupling constant in the range $10^{-13}\leq g_{ae}\leq 10^{0}$.

hep-ph

Probing Virtual Axion-Like Particles by Precision Phase Measurements

We propose an experiment for detecting Axion-Like Particles (ALPs) based on the axion-photon interaction in the presence of a non-uniform magnetic field. The impact of virtual ALPs on the polarization of the photons inside a cavity is studied and a detection scheme is proposed. We find that the cavity normal modes are dispersed differently owing to their coupling to the ALPs in the presence of a background magnetic field. This birefringence, in turn, can be observed as a phase difference between the cavity polarization modes. The signal is considerably enhanced for a squeezed light source. We argue that the amplified signal allows for exclusion of a range of axion mass $6\times10^{-4}\text{eV}\lesssim m_{a}\lesssim 6\times10^{-3}\text{eV}$ even at very small axion-photon coupling constant with the potential to reach sensitivity to the QCD axion. Our scheme allows for the exclusion of a range of axion masses that has not yet been covered by other experimental techniques.

hep-ph