Science China Physics, Mechanics & Astronomy最新文献

Anderson localization describes disorder-induced phase transitions, distinguishing between localized and extended states. In quasiperiodic systems, a third multifractal state emerges, characterized by unique energy and wave functions. However, the corresponding multifractal-enriched mobility edges and three-state-coexisting quantum phases have yet to be experimentally detected. In this work, we propose exactly solvable one-dimensional quasiperiodic lattice models that simultaneously host three-state-coexisting quantum phases, with their phase boundaries analytically derived via Avilas global theorem. Furthermore, we propose experimental protocols via Rydberg atom arrays to realize these states. Notably, we demonstrate a spectroscopic technique capable of measuring inverse participation ratios across real-space and dual-space domains, enabling simultaneous characterization of localized, extended, and multifractal quantum phases in systems with up to tens of qubits. Our work opens new avenues for the experimental exploration of Anderson localization and multifractal states in artificial quantum systems.

Atomic surface mobility of glasses plays an important role in understanding glass dynamics and determining many fundamental processes on the surface. However, the diffusion dynamics at the free surface in marginal glasses remains unknown due to limited glass formation ability. In this study, we systematically investigate surface diffusion and relaxation behavior in four marginal glass-forming Fe-based metallic glasses with great application potential. Surface diffusion rates in marginal glass- forming Fe-based metallic glasses are significantly faster than those of stable metallic glasses. For the first time, an abnormal β_t relaxation mode with thermal activation character is identified between α and β relaxation. Strikingly, the activation energy of surface diffusion matches that of β_t relaxation. A mechanism involving cooperative cluster motion associated with β_t relaxation is proposed to explain the ultrafast surface diffusion. These results establish a direct correlation between surface diffusion and bulk relaxation, providing a basis for tailoring surface properties in metallic glasses.

The Kirkwood-Dirac (KD) distribution is a vital framework in quantum state characterization, which reveals nonclassical correlations through phase-space representations. In this work, we introduce trace-norm-based measures to assess the KD-nonclassicality of quantum states and derive the corresponding trade-off relations for qubit and qutrit systems. For a bipartite state shared by Alice and Bob and a set of measurements applied by Alice, the maximum value of the totally averaged quantum resource of Bob’s states is introduced with respect to a quantum resource quantifier. When the maximum value exceeds the upper bound in a trade-off relation, the bipartite state is said to exhibit nonlocal advantages of quantum resource (NAQR). We prove that a state exhibiting NAQR, such as nonlocal advantages of KD-nonclassicality (NAKDNC), is steerable from Alice to Bob. We demonstrate that NAKDNC of Werner states exhibit much more quantum steering than quantum coherence and quantum imaginarity do and also explore NAKDNC of the two-qutrit isotropic states. These findings emerge KD-nonclassicality as an independent nonclassical resource with operational relevance in quantum information protocols.

Coherent, periodic radio emission from pulsars has been widely interpreted as evidence of neutron stars as strongly magnetized compact objects. In recent years, radio pulses have also been detected from white dwarfs (WDs) in tight binary systems, raising the question of whether isolated WDs could similarly host pulsar-like emission. We conducted the most sensitive search to date for coherent radio signals from five isolated, rapidly rotating, and magnetized WDs, using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), the Green Bank Telescope (GBT), and the Australia Telescope Compact Array (ATCA). No pulsed or continuum radio emission was detected down to μJy levels. These non-detections place the most stringent observational constraints yet on the existence of isolated WD pulsars. Our results suggest that either such emission is intrinsically weak, narrowly beamed, or requires binary-induced magnetospheric interactions absent in solitary systems. Comparison with the known radio-emitting WDs highlights the critical role of companion interaction in enabling detectable emission. This work expands on prior surveys by targeting sources with the most favorable physical conditions for WD pulsar-like activity and employing highly sensitive, targeted observations. Future observations with next-generation facilities such as the SKA will be essential to explore fainter or sporadic emission from massive, magnetic WDs and to investigate their potential as compact radio transients further.

Scheduled for launch in 2030, the enhanced X-ray Timing and Polarization (eXTP) telescope is a Chinese space-based mission aimed at studying extreme conditions and phenomena in astrophysics. eXTP will feature three main payloads: Spectroscopy Focusing Array (SFA), Polarimetry Focusing Array (PFA), and a Wide-field Camera (W2C). This white paper outlines observatory science, incorporating key scientific advances and instrumental changes since the publication of the previous white paper. We will discuss perspectives of eXTP on the research domains of flare stars, supernova remnants, pulsar wind nebulae, cataclysmic variables, X-ray binaries, ultraluminous X-ray sources, active galactic nucleus (AGN), and pulsar-based positioning and timekeeping.

In this paper we present the science potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission, in its new configuration, for studies of strongly magnetized compact objects. We discuss the scientific potential of eXTP for quantum electrodynamic (QED) studies, especially leveraging the recent observations made with the NASA IXPE mission. Given eXTP’s unique combination of timing, spectroscopy, and polarimetry, we focus on the perspectives for physics and astrophysics studies of strongly magnetized compact objects, such as magnetars and accreting X-ray pulsars. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to launch in early 2030.

In this new era of time-domain and multi-messenger astronomy, various new transients and new phenomena are constantly being discovered thanks to the rapid advances in observations, which provide the excellent opportunity to study the physics in the extreme environments. The enhanced X-ray Timing and Polarimetry mission (eXTP), planned to be launched in 2030, has several key advantages, including advanced polarimetry, high sensitivity & large effective area, and wide energy range coverage, which make it a groundbreaking project in high-energy astrophysics. In this article, we briefly introduce the potential time-domain and multi-messenger targets for eXTP, including gravitational-wave (GW) counterparts, gamma-ray bursts (GRBs), magnetars and fast radio bursts (FRBs), tidal disruption events (TDEs), supernovae, high energy neutrinos and TeV active galactic nucleus (AGNs), and so on. We discuss the advantages of future eXTP observations for detecting these sources, their detection capabilities, the abilities to distinguish theoretical models, and their applications in gravity and cosmology.

In this paper, we present the current status of the enhanced X-ray Timing and Polarimetry mission, which has been fully approved for launch in 2030. eXTP is a space science mission designed to study fundamental physics under extreme conditions of matter density, gravity, and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring the effects of quantum electro-dynamics, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, the eXTP mission is poised to become a leading observatory for time-domain and multi-messenger astronomy in the 2030s, as well as providing observations of unprecedented quality on a variety of galactic and extragalactic objects. After briefly introducing the history and a summary of the scientific objectives of the eXTP mission, this paper presents a comprehensive overview of: (1) the cutting-edge technology, technical specifications, and anticipated performance of the mission’s scientific instruments; (2) the full mission profile, encompassing spacecraft design, operational capabilities, and ground segment infrastructure.