arXiv subjects

Haorong Wu

Publications and source records attributed to Haorong Wu.

6 recordsLinked to original sources

arXiv2026

Quantum transitions of vector vortex light in gravitational waves

We develop a theoretical framework to describe the full interaction between vector vortex light fields and gravitational waves (GWs). Using perturbation theory and the canonical quantization of the electromagnetic field, we calculate the quantum transition probabilities of vector Bessel beams propagating through GWs. We demonstrate that GWs induce fourteen different quantum transition channels across orbital angular momentum (OAM) $l$ and spin angular momentum (SAM) $\sigma$, mapping initial states $\ket{\sigma,l}$ to $\ket{\sigma+\Delta \sigma,l+j-\Delta \sigma}$, where $\Delta\sigma \in \{-2, 0, 2\}$ represents the change in SAM and $j \in \{-3, \dots, 3\}$ denotes the change in total angular momentum. Among these channels, SAM-conserving transitions between OAM states, specifically $\ket{\sigma, l}\rightarrow \ket{\sigma, l\pm 1}$, provide the most viable mechanism for experimental detection. Conversely, spin-flip transitions are shown to be heavily suppressed relative to OAM transitions. Additionally, the reversal of SAM induces an asymmetric shift in the OAM transition channels, reflecting the underlying coupling between SAM and OAM during the gravitational interaction. Based on these transition channels, we propose a new cavity-based GW detection configuration. By relying on quantum transitions rather than macroscopic arm-length changes, this scheme is inherently insensitive to displacement-based disturbances like seismic noise, offering a new paradigm and frequency bands for GW observation.

gr-qc↗

arXiv2026

First-Order Perturbations of Covariant Maxwell Equations in Gravitational Waves

We present a systematic theoretical framework for investigating first-order electromagnetic (EM) perturbations induced by gravitational waves (GWs). Beginning with the covariant Maxwell equations, we derive the complete first-order perturbation equations in terms of both the EM field tensor and the four-potential, demonstrating their equivalence alongside the residual gauge invariance under the Lorenz gauge condition. Furthermore, explicit first-order expressions for the induced electric and magnetic fields, as well as the associated EM energy-momentum tensor, are obtained. As an explicit illustration, we analytically evaluate the interaction between a plane EM wave and a GW within the transverse-traceless gauge. By demonstrating that the maximum modulus of the coupling coefficient is on the order of $10^2$, we quantitatively establish that a typical astrophysical GW with a dimensionless strain of $h_0 \sim 10^{-21}$ generates a first-order EM response on the order of $10^{-19}$ relative to the incident field amplitude.

gr-qc↗

arXiv2026

Chiroptical effect induced by gravitational waves

We propose the gravitational analog of the chiroptical effect for the first time, demonstrating that gravitational waves (GWs) can induce a reversal of photon chirality through the exchange of angular momentum, namely the spin-2-gravitation chiroptical effect. By analyzing the interaction between photon spin angular momentum (SAM) and GWs, we derive the selection rules governing this exchange, which are strictly dictated by the spin-1 and spin-2 nature of the electromagnetic and gravitational fields, respectively. We find that the gravitational chiroptical effect reflects the local nature of SAM which prevents the accumulation of gravitational perturbations over spatial phase windings, and offers a theoretically rigorous tool to probe the chiral structure of GWs. This mechanism provides a novel observational pathway to constrain modified gravity theories, measure the asymmetric properties of compact binaries, and explore parity-violating physics in the early universe.

gr-qc↗

arXiv2025

How gravitational waves change photon orbital angular momentum quantum states

We explore the evolution of vortex light in the presence of gravitational waves (GWs) and demonstrate that the quantized orbital angular momentum (OAM) states can make transitions to other states due to the GWs. The interaction is calculated based on the framework of the wave propagation in linearized gravity theory and canonical quantization of the light field in curved spacetime. It is found that when a photon possessing OAM of $l$ interacts with GWs, the OAM modes of $l\pm1$ and $l\pm2$ may be excited with probabilities of $P_{l\pm1}\sim 10^{-17}$ and $P_{l\pm2}\sim 10^{-20}$, respectively. Higher probabilities of the transitions can be achieved when the photon radial wave vector or the propagation distance is increased, or when the photons encounter GWs with stronger amplitudes or smaller frequencies. Thus, a new GW detection technique is proposed, which may exhibit good performance in a wide range of GW frequencies. Furthermore, the detector is insensitive to seismic noise and is more advantageous for determining the distance of the source compared to current interferometer detectors.

gr-qc↗

arXiv2024

Orbital angular momentum spectrum and entanglement in a rotating accelerated reference frame

The particle definition varies across different theories. The quantum field theory in curved spacetime shows that from the perspective of a linearly accelerated observer, an inertial empty space may be full of thermal particles. This effect is known as the Unruh effect. When the degrees of freedom of orbital angular momentum (OAM) are considered, all OAM modes share the same expected particle number. Here, we examine the OAM spectrum in a rotating accelerated reference frame to see how the spectrum differs from the linear accelerated case. When the observer starts to rotate, not all OAM modes are allowed and some negative energy modes show up. To understand how a rotating accelerated observer actually perceives these particles, the Unruh-DeWitt detector and its detailed balance are studied. This relation is studied both in the comoving inertial frame and in the rest frame. Based on these results, the OAM entanglement degradation is explored in two-dimensional and high-dimensional cases, respectively. The results indicate that the entanglement dimension and the highest order of OAM modes are mainly related to the acceleration and the rotation, respectively. It is then demonstrated that these results can be generalized to all stationary trajectories.

gr-qc↗

arXiv2022

How gravitational fluctuations degrade the high-dimensional spatial entanglement

Twisted photons carrying orbital angular momentum (OAM) are competent candidates for future interstellar communications. However, the gravitational fluctuations are ubiquitous in spacetime. Thus a fundamental question arises naturally as to how the gravitational fluctuations affect the coherence and the degree of high-dimensional OAM entanglement when twisted photons travel across the textures of curved spacetime. Here, we consider the covariant scalar Helmholtz equations and the Minkowski metric with fluctuations of Gaussian distribution and formulate analytically the equations describing the motion for twisted light in the Laguerre-Gaussian mode space. It is seen that the OAM cannot remain conserved in the presence of gravitational fluctuations. Furthermore, two-photon density matrices are derived for interstellar OAM quantum entanglement distribution, and the degree of entanglement degradation is characterized by purity and negativity. It is revealed that the higher-dimensional OAM entanglement is more susceptible to spacetime fluctuations. We believe that our findings will be of fundamental importance for the future interstellar quantum communications with twisted photons.

quant-ph↗