arXiv subjects

Shun Wang

Publications and source records attributed to Shun Wang.

At least 37 records · Page 2Linked to original sources

arXiv2025

High-frequency magnetic response measurement of test mass with a fluxgate magnetometer for gravitational wave detection

For space-borne gravitational wave detectors,such as LISA and TianQin ,the disturbance caused by the coupling of test masses and the external magnetic fields is one of the main sources of the residual acceleration noise. Although the detection frequency band is from 0.1 mHz to 1 Hz, magnetic fields with frequencies higher than 1 Hz can still contribute to the noise through down conversion effect. Therefore, it is necessary to measure the AC magnetic susceptibility or magnetic response of the test mass at higher frequency for the evaluation of the magnetic noise. In this work, we propose a magnetic field response measurement method by directly probing the induced magnetic field of the test mass placed in a spatially uniform magnetic field. The frequency can be measured up to 1500 Hz, satisfying the requirement of space-borne gravitational wave detection.

physics.ins-det↗

arXiv2025

Progress of the TianQin project

TianQin is a future space-based gravitational wave observatory targeting the frequency window of $10^{-4}$ Hz $\sim 1$ Hz. A large variety of gravitational wave sources are expected in this frequency band, including the merger of massive black hole binaries, the inspiral of extreme/intermediate mass ratio systems, stellar-mass black hole binaries, Galactic compact binaries, and so on. TianQin will consist of three Earth orbiting satellites on nearly identical orbits with orbital radii of about $10^5$ km. The satellites will form a normal triangle constellation whose plane is nearly perpendicular to the ecliptic plane. The TianQin project has been progressing smoothly following the ``0123" technology roadmap. In step ``0", the TianQin laser ranging station has been constructed and it has successfully ranged to all the five retro-reflectors on the Moon. In step ``1", the drag-free control technology has been tested and demonstrated using the TianQin-1 satellite. In step ``2", the inter-satellite laser interferometry technology will be tested using the pair of TianQin-2 satellites. The TianQin-2 mission has been officially approved and the satellites will be launched around 2026. In step ``3", i.e., the TianQin-3 mission, three identical satellites will be launched around 2035 to form the space-based gravitational wave detector, TianQin, and to start gravitational wave detection in space.

gr-qc↗

arXiv2025

FEASTS: The Fate of Gas and Star Formation in Interacting Galaxies

We use HI data from the FAST Extended Atlas of Selected Targets Survey (FEASTS) to study the interplay between gas and star formation of galaxies in interacting systems. We build control and mock HI disks and parameterize HI disorder by a series of disorder parameters, describing the piling, clumpiness and expansion of HI. We find that interacting galaxies have higher HI disorder described by almost all disorder parameters. Systems with comparable stellar masses and small relative velocities tend to have stronger expansion and clumpiness of HI. At a given stellar mass, decreased HI and total neutral gas mass and suppressed star formation rate of secondary galaxies are correlated with most disorder parameters. For primary galaxies, HI and total neutral gas deficiency correlate with more HI piling at two ends of the system outside HI disks but not with the expansion or clumpiness of HI. We also find that the HI surface densities of both primary and secondary galaxies are lower within the HI disks and higher outside compared to the control galaxies. Our results suggest that while all the disorder parameters quantify the interaction strength almost equally well, they have different sensitivities in tracing star formation rate and gas mass enhancements. They also imply that while gas removal likely dominates the tidal effects on secondary galaxies, primary galaxies experience more complex situation that are possibly related to gas depletion and accretion happening at different interaction stages.

astro-ph.GA↗

arXiv2024

MMTE: Corpus and Metrics for Evaluating Machine Translation Quality of Metaphorical Language

Machine Translation (MT) has developed rapidly since the release of Large Language Models and current MT evaluation is performed through comparison with reference human translations or by predicting quality scores from human-labeled data. However, these mainstream evaluation methods mainly focus on fluency and factual reliability, whilst paying little attention to figurative quality. In this paper, we investigate the figurative quality of MT and propose a set of human evaluation metrics focused on the translation of figurative language. We additionally present a multilingual parallel metaphor corpus generated by post-editing. Our evaluation protocol is designed to estimate four aspects of MT: Metaphorical Equivalence, Emotion, Authenticity, and Quality. In doing so, we observe that translations of figurative expressions display different traits from literal ones.

cs.CL↗

arXiv2024

Circular Photocurrents in Centrosymmetric Semiconductors with Hidden Spin Polarization

Centrosymmetric materials with site inversion asymmetries possess hidden spin polarization, which remains challenging to be converted into spin currents because the global inversion symmetry is still conserved. This study demonstrates the spin-polarized DC circular photocurrents (CPC) in centrosymmetric transition metal dichalcogenides (TMDCs) at normal incidence without applying electric bias. The global inversion symmetry is broken by using a spatially-varying circularly polarized light beam, which could generate spin gradient owing to the hidden spin polarization. The dependences of the CPC on electrode configuration, illumination position, and beam spot size indicate an emergence of circulating electric current under spatially inhomogeneous light, which is associated with the deflection of spin-polarized current through the inverse spin Hall effect (ISHE). The CPC is subsequently utilized to probe the spin polarization and ISHE under different excitation wavelengths and temperatures. The results of this study demonstrate the feasibility of using centrosymmetric materials with hidden spin polarization and non-vanishing Berry curvature for spintronic device applications.

cond-mat.mtrl-sci↗

arXiv2024

FEASTS Combined with Interferometry (I): Overall Properties of Diffuse HI and Implications for Gas Accretion in Nearby Galaxies

We present a statistical study of the properties of diffuse HI in ten nearby galaxies, comparing the HI detected by the single-dish telescope FAST (FEASTS program) and the interferometer VLA (THINGS program), respectively. The THINGS' observation missed HI with a median of 23% due to the short-spacing problem of interferometry and limited sensitivity. We extract the diffuse HI by subtracting the dense HI, which is obtained from the THINGS data with a uniform flux-density threshold, from the total HI detected by FAST. Among the sample, the median diffuse-HI fraction is 34%, and more diffuse HI is found in galaxies exhibiting more prominent tidal-interaction signatures. The diffuse HI we detected seems to be distributed in disk-like layers within a typical thickness of $1\,\text{kpc}$, different from the more halo-like diffuse HI detected around NGC 4631 in a previous study. Most of the diffuse HI is cospatial with the dense HI and has a typical column density of $10^{17.7}$-$10^{20.1}\,\text{cm}^{-2}$. The diffuse and dense HI exhibits a similar rotational motion, but the former lags by a median of 25% in at least the inner disks, and its velocity dispersions are typically twice as high. Based on a simplified estimation of circum-galactic medium properties and assuming pressure equilibrium, the volume density of diffuse HI appears to be constant within each individual galaxy, implying its role as a cooling interface. Comparing with existing models, these results are consistent with a possible link between tidal interactions, the formation of diffuse HI, and gas accretion.

astro-ph.GA↗

arXiv2024

Ba6RE2Ti4O17 (RE= Nd, Sm,Gd, Dy-Yb): A family of Rare-earth based layered triangular lattice magnets

Rare-earth-based triangular-lattice magnets provide the fertile ground to explore the exotic quantum magnetic state. Herein, we report a new family of RE-based triangular-lattice magnets Ba6RE2Ti4O17(RE= rare earth ions) crystallized into the hexagonal structure with space group of P63 mmc, where magnetic rare earth ions form an ideal triangular lattice within the ab-plane and stack in an AA -type fashion along the c-axis. The low-temperature magnetic susceptibility results reveal all the serial compounds have the dominant antiferromagnetic interactions and an absence of magnetic ordering down to 1.8 K. The magnetization and electron spin resonance results indicate distinct magnetic anisotropy for the compounds with different RE ions. Moreover, Ba6Nd2Ti4O17 single crystal is successfully grown and it exhibits strong Ising like anisotropy with magnetic easy-axis perpendicular to the triangle-lattice plane, being a candidate to explore quantum spin liquid state with dominant Ising-type interaction.

cond-mat.mtrl-sci↗

arXiv2024

Sliding-mediated ferroelectric phase transition in CuInP2S6 under pressure

Interlayer stacking order has recently emerged as a unique degree of freedom to control crystal symmetry and physical properties in two-dimensional van der Waals (vdW) materials and heterostructures. By tuning the layer stacking pattern, symmetry-breaking and electric polarization can be created in otherwise non-polar crystals, whose polarization reversal depends on the interlayer sliding motion. Herein, we demonstrate that in a vdW layered ferroelectric, its existing polarization is closely coupled to the interlayer sliding driven by hydrostatic pressure. Through combined structural, electrical, vibrational characterizations, and theoretical calculations, we clearly map out the structural evolution of CuInP2S6 under pressure. A tendency towards a high polarization state is observed in the low-pressure region, followed by an interlayer-sliding-mediated phase transition from a monoclinic to a trigonal phase. Along the transformation pathway, the displacive-instable Cu ion serves as a pivot point that regulates the interlayer interaction in response to external pressure. The rich phase diagram of CuInP2S6, which is enabled by stacking orders, sheds light on the physics of vdW ferroelectricity and opens an alternative route to tailoring long-range order in vdW layered crystals.

cond-mat.mtrl-sci↗

arXiv2023

Improving Biomedical Abstractive Summarisation with Knowledge Aggregation from Citation Papers

Abstracts derived from biomedical literature possess distinct domain-specific characteristics, including specialised writing styles and biomedical terminologies, which necessitate a deep understanding of the related literature. As a result, existing language models struggle to generate technical summaries that are on par with those produced by biomedical experts, given the absence of domain-specific background knowledge. This paper aims to enhance the performance of language models in biomedical abstractive summarisation by aggregating knowledge from external papers cited within the source article. We propose a novel attention-based citation aggregation model that integrates domain-specific knowledge from citation papers, allowing neural networks to generate summaries by leveraging both the paper content and relevant knowledge from citation papers. Furthermore, we construct and release a large-scale biomedical summarisation dataset that serves as a foundation for our research. Extensive experiments demonstrate that our model outperforms state-of-the-art approaches and achieves substantial improvements in abstractive biomedical text summarisation.

cs.CL↗

arXiv2023

ALMA/ACA CO Survey of the IC 1459 and NGC 4636 Groups: Environmental Effects on the Molecular Gas of Group Galaxies

We present new results of a 12CO(J=1-0) imaging survey using the Atacama Compact Array (ACA) for 31 HI detected galaxies in the IC 1459 and NGC 4636 groups. This is the first CO imaging survey for loose galaxy groups. We obtained well-resolved CO data (~0.7-1.5 kpc) for a total of 16 galaxies in two environments. By comparing our ACA CO data with the HI and UV data, we probe the impacts of the group environment on the cold gas components (CO and HI gas) and star formation activity. We find that CO and/or HI morphologies are disturbed in our group members, some of which show highly asymmetric CO distributions (e.g., IC 5264, NGC 7421, and NGC 7418). In comparison with isolated galaxies in the xCOLD GASS sample, our group galaxies tend to have low star formation rates and low H2 gas fractions. Our findings suggest that the group environment can change the distribution of cold gas components, including the molecular gas, and star formation properties of galaxies. This is supporting evidence that preprocessing in the group-like environment can play an important role in galaxy evolution.

astro-ph.GA↗

arXiv2023

Spatial-spectral mapping to prepare the frequency entangled qudits

Entangled qudits, the high-dimensional entangled states, play an important role in the study of quantum information. How to prepare entangled qudits in an efficient and easy-to-operate manner is still a challenge in quantum technology. Here, we demonstrate a method to engineer frequency entangled qudits in a spontaneous parametric downconversion process. The proposal employs an angle-dependent phase-matching condition in a nonlinear crystal, which forms a classical-quantum mapping between the spatial (pump) and spectral (biphotons) degrees of freedom. In particular, the pump profile is separated into several bins in the spatial domain, and thus shapes the down-converted biphotons into discrete frequency modes in the joint spectral space. Our approach provides a feasible and efficient method to prepare a high-dimensional frequency entangled state. As an experimental demonstration, we generate a three-dimensional entangled state by using a homemade variable slit mask.

quant-ph↗

arXiv2023

FAST-ASKAP Synergy: Quantifying Coexistent Tidal and Ram Pressure Strippings in the NGC 4636 Group

Combining new HI data from a synergetic survey of ASKAP WALLABY and FAST with the ALFALFA data, we study the effect of ram pressure and tidal interactions in the NGC 4636 group. We develop two parameters to quantify and disentangle these two effects on gas stripping in HI-bearing galaxies: the strength of external forces at the optical-disk edge, and the outside-in extents of HI-disk stripping. We find that gas stripping is widespread in this group, affecting 80% of HI-detected non-merging galaxies, and that 41% are experiencing both types of stripping. Among the galaxies experiencing both effects, the two types of strengths are independent, while two HI-stripping extents moderately anticorrelate with each other. Both strengths are correlated with HI-disk shrinkage. The tidal strength is related to a rather uniform reddening of low-mass galaxies ($M_*<10^9\,\text{M}_\odot$) when tidal stripping is the dominating effect. In contrast, ram pressure is not clearly linked to the color-changing patterns of galaxies in the group. Combining these two stripping extents, we estimate the total stripping extent, and put forward an empirical model that can describe the decrease of HI richness as galaxies fall toward the group center. The stripping timescale we derived decreases with distance to the center, from $\mathord{\sim}1\,\text{Gyr}$ beyond $R_{200}$ to $\mathord{\lesssim}10\,\text{Myr}$ near the center. Gas-depletion happens $\mathord{\sim}3\,\text{Gyr}$ since crossing $2R_{200}$ for HI-rich galaxies, but much quicker for HI-poor ones. Our results quantify in a physically motivated way the details and processes of environmental-effects-driven galaxy evolution, and might assist in analyzing hydrodynamic simulations in an observational way.

astro-ph.GA↗

arXiv2023

Exploring the interfacial coupling between graphene and the antiferromagnetic insulator MnPSe$_3$

Interfacial coupling between graphene and other 2D materials can give rise to intriguing physical phenomena. In particular, several theoretical studies predict that the interplay between graphene and an antiferromagnetic insulator could lead to the emergence of quantum anomalous Hall phases. However, such phases have not been observed experimentally yet, and further experimental studies are needed to reveal the interaction between graphene and antiferromagnetic insulators. Here, we report the study in heterostructures composed of graphene and the antiferromagnetic insulator MnPSe$_3$. It is found that the MnPSe$_3$ has little impact on the quantum Hall phases apart from doping graphene via interfacial charge transfer. However, the magnetic order can contribute indirectly via process like Kondo effect, as evidenced by the observed minimum in the temperature-resistance curve between 20-40 K, far below the Néel temperature (70 K).

cond-mat.mtrl-sci↗

arXiv2023

On the noise effect of test mass surface roughness in spaceborne gravitational wave detectors

Spaceborne gravitational wave detection mission has a demanding requirement for the precision of displacement sensing, which is conducted by the interaction between the laser field and test mass. However, due to the roughness of the reflecting surface of the test mass, the displacement measurement along the sensitive axis suffers a coupling error caused by the residue motion of other degrees of freedom. In this article, we model the coupling of the test mass residue random motion to the displacement sensing along the sensitive axis and derived an analytical formula of the required precision of the surface error for the spaceborne gravitational wave detectors. Our result shows that this coupling error will not contaminate the picometer displacement sensing for the test masses in the LISA pathfinder.

physics.ins-det↗

arXiv2023

Metaphor Detection via Explicit Basic Meanings Modelling

One noticeable trend in metaphor detection is the embrace of linguistic theories such as the metaphor identification procedure (MIP) for model architecture design. While MIP clearly defines that the metaphoricity of a lexical unit is determined based on the contrast between its \textit{contextual meaning} and its \textit{basic meaning}, existing work does not strictly follow this principle, typically using the \textit{aggregated meaning} to approximate the basic meaning of target words. In this paper, we propose a novel metaphor detection method, which models the basic meaning of the word based on literal annotation from the training set, and then compares this with the contextual meaning in a target sentence to identify metaphors. Empirical results show that our method outperforms the state-of-the-art method significantly by 1.0\% in F1 score. Moreover, our performance even reaches the theoretical upper bound on the VUA18 benchmark for targets with basic annotations, which demonstrates the importance of modelling basic meanings for metaphor detection.

cs.CL↗

arXiv2023

The ISM scaling relations using inner HI and an application of estimating dust mass

We select a disk-like galaxy sample with observations of the $HI$, $H_{2}$ and dust from Herschel Reference Survey (HRS), and derive inner HI masses within the optical radius. We find that the inner gas-to-dust ratio is almost independent of gas-phase metallicity, and confirm that the inner gas mass ($HI$+$H_{2}$) shows tighter relationship with dust mass and monochromatic 500 $μm$ luminosity than the integral gas mass. It supports that dust is more closely associated with co-spatial cold gas than the overall cold gas. Based on the newly calibrated relationship between inner gas mass and dust mass, we predict dust masses for disk-dominated galaxies from the xCOLD GASS sample. The predicted dust masses show scaling relations consistent with fiducial ones in the literature, supporting their robustness. Additionally, we find that at a given dust mass and star formation rate (SFR), the galactic WISE W3 luminosities show significant dependence on the [NII] luminosity and the stellar mass surface density. Such dependence highlights the caveat of using the W3 luminosity as integral SFR indicator, and is consistent with findings of studies which target star-forming regions in more nearby galaxies and accurately derive dust masses based on mapping-mode spectroscopy.

astro-ph.GA↗

arXiv2023

Metaphor Detection with Effective Context Denoising

We propose a novel RoBERTa-based model, RoPPT, which introduces a target-oriented parse tree structure in metaphor detection. Compared to existing models, RoPPT focuses on semantically relevant information and achieves the state-of-the-art on several main metaphor datasets. We also compare our approach against several popular denoising and pruning methods, demonstrating the effectiveness of our approach in context denoising. Our code and dataset can be found at https://github.com/MajiBear000/RoPPT

cs.CL↗

arXiv2023

FrameBERT: Conceptual Metaphor Detection with Frame Embedding Learning

In this paper, we propose FrameBERT, a RoBERTa-based model that can explicitly learn and incorporate FrameNet Embeddings for concept-level metaphor detection. FrameBERT not only achieves better or comparable performance to the state-of-the-art, but also is more explainable and interpretable compared to existing models, attributing to its ability of accounting for external knowledge of FrameNet.

cs.CL↗