Science China Physics, Mechanics & Astronomy最新文献

Quantum information processing platforms based on array of matter qubits, such as neutral atoms, trapped ions, and quantum dots, face significant challenges in scalable addressing and readout as system sizes increase. Here, we propose the “Volcano” architecture that establishes a new quantum processing unit implementation method based on optical channel mapping on an arbitrarily arranged static qubit array. To support the feasibility of Volcano architecture, we show a proof-of-principle demonstration by employing a photonic chip that leverages custom-designed three-dimensional waveguide structures to transform one-dimensional beam arrays into arbitrary two-dimensional output patterns matching qubit array geometries. We demonstrate parallel and independent control of 49-channel system with negligible crosstalk and high uniformity. This architecture addresses the challenges in scaling up quantum processors, including both the classical link for parallel qubit control and the quantum link for efficient photon collection, and holds the potential for interfacing with neutral atom arrays and trapped ion crystals, as well as networking of heterogeneous quantum systems.

The nitrogen-vacancy (NV) center in diamond is a point defect formed by a substitutional nitrogen atom adjacent to a carbon vacancy. Owing to its exceptional fluorescence properties and long quantum coherence, the NV center has broad applications in quantum computing, quantum sensing, and magnetic field imaging. This study focuses on the magnetic field sensing capabilities of NV centers, with performance critically dependent on the NV concentrations and coherence time. High-performance NV center diamond samples were synthesized using microwave plasma chemical vapor deposition (MPCVD) with controlled nitrogen doping, followed by electron irradiation and high-temperature annealing. We obtained diamond samples with high NV concentrations and a coherence time of T₂^* = 0.48 µs. These diamonds were processed into micrometer-sized crystals via laser cutting and polishing, then integrated into an optical fiber-based probe for magnetic field detection. The sensor’s performance was first characterized independently, with a magnetic sensitivity of 5.77 ({rm nT}/{sqrt {rm Hz}}) and a magnetic resolution of 0.1 G@4715 G. Subsequently, two-dimensional magnetic field imaging experiments were performed on chip surfaces, demonstrating the probe’s capability for precise mapping of local magnetic fields.

We propose a data-driven physics-informed neural networks (PINNs) via task-decomposition (DD-PINNs-TD) for modeling nonlinear thermal-deformation-polarization-carrier (TDPC) coupling mechanical behaviors of piezoelectric semiconductors (PSs). By embedding three-dimensional (3D), plate, and beam equations of PS structures into the constraints of the DD-PINNs-TD framework, respectively, we develop three representative PINNs that exhibit significant advantages in computational efficiency and accuracy compared to traditional PINNs. Using the proposed DD-PINNs-TD models, we investigate the TDPC coupling responses of PS structures under different loadings. Numerical results demonstrate that the proposed models exhibit accuracy and stability of these models in predicting the nonlinear multi-field coupling mechanical behaviors of PSs. Notably, the plate and beam-theory-based DD-PINNs-TD models achieve superior computational efficiency relative to their 3D-equation-based counterparts. This study establishes a theoretical foundation for analyzing nonlinear multi-field coupling responses in PS structures and has significant practical value in engineering applications.

Majorana zero modes (MZMs) are the most intensively studied non-Abelian anyons. The Dirac fermion zero modes in topological insulators, which are symmetry-protected doubling of MZMs under fermion number conservation, offer an alternative approach to explore non-Abelian anyons. However, a unified model that elucidates the braiding statistics of these types of topological zero modes remains absent. We show that the minimal Kitaev chain model beyond fine-tuning regime provides a unified characterization of the non-Abelian statistics of both MZMs and Dirac fermion zero modes in different parameter regimes. In particular, we introduce a minimal tri-junction setting based on the minimal Kitaev chain model and show it facilitates the unified scheme of braiding Dirac fermion zero modes, as well as the MZMs in the assistance of a Dirac mode. This unified minimal model provides deeper insights into non-Abelian statistics, demonstrating that the non-Abelian braiding of MZMs can be continuously extended to encompass Dirac fermion zero modes. The minimal Kitaev chain has been realized in coupled quantum dots (Nature 614, 445 (2023); Nature 641, 890 (2025)). Our extension, which demonstrates novel nontrivial phases with non-Abelian MZM pairs and Dirac zero modes emerging in the broader parameter regimes without fine-tuning, expands the accessible experimental parameter space and enhances the feasibility of observing non-Abelian statistics in the minimal Kitaev chain model.

Charged particle precipitation typically manifests as a gradual increase and decrease of flux observed by space detectors. Cases with rapid flux variation are very rare, while periodic events are even more extraordinary. These oscillating particle precipitation (OPP) events are usually attributed to the bounce motion of electrons probably induced by lightning. However, the origin of these oscillation events is still on debate. Here we report three peculiar charged particle precipitation events detected by GECAM during a geomagnetic storm on March 21, 2024, with two exhibiting significant periodicity. These events were observed around the same region during three consecutive orbits with a life time of more than 3.5 h. Through comprehensive temporal and spectral analyses, we find that one of the OPP events exhibited a transition in spectral lag of mini-pulses, shifting from “softer-earlier” to “softer-later” while showing no significant time evolution in overall frequency characteristics, and that there is no association found between these two OPP events and lightning activity nearby. Finally, we discussed possible scenarios to explain these GECAM-detected OPP events, and we found that they may represent a new type of particle precipitation event or a peculiar lightning-induced electron precipitation (LEP).

The bulk-boundary correspondence, which establishes the relationship between bulk topological invariants and the number of protected edge states, has been both theoretically and experimentally verified. However, some recent theoretical studies have demonstrated the breakdown of bulk-boundary correspondence caused by specific symmetries where the entanglement spectrum, rather than the edge spectrum, could manifest the bulk topology more generally. Due to the difficulties in measuring this in physical systems, the bulk-entanglement spectrum correspondence has not yet been experimentally confirmed. Here, we report several one-dimensional and two-dimensional acoustic crystals in which we experimentally probe the nonlocal correlations with the fermion filling analog, thereby verifying the above correspondence. This work provides a useful platform to study the interplay among topological phases, symmetries, and the entanglement spectrum.

This study investigated the hydrodynamic instability on a liquid-gas interface and its dependence on initial conditions. A drop tower method was employed to generate a quasi-single-mode water-air interface and also finite pulse accelerations. The finite pulse was produced by releasing a water tank onto coil springs, achieving a peak acceleration of 193 times the gravity acceleration within 5 ms. The experiments highlighted the transition from Rayleigh-Taylor (RT) stabilization to near Richtmyer-Meshkov (near-RM) instability. The results demonstrated that bubble and spike development is dominated by RT stabilization during pulse acceleration and near-RM instability after pulse. The different behaviors of bubbles and spikes under high-Atwood-number conditions were observed, noting perturbation phase reversals and the formation of a high-speed water jet. Spectral analysis of the interface contour and time-varying Fourier mode amplitudes revealed that the bubble development is suppressed by nonlinear effect while the spike instability is markedly enhanced by flow focusing. A sink-flow model was developed to evaluate the water jet velocity induced by the depthwise flow focusing, validated through impact experiments on an initially unperturbed interface. Finally, a comprehensive nonlinear solution was established for quantifying the hydrodynamic instabilities on a water-air interface, incorporating variable acceleration, nonlinear effects, and flow focusing.

The thermodynamic inconsistency observed in regular black holes is resolved through the framework of reduced thermodynamic phase spaces. We demonstrate that regular black holes are essentially induced from singular black holes by adding an extra requirement, which imposes a constraint among black hole parameters. This constraint reduces the thermodynamic phase space, rendering the standard form of the first law of black hole thermodynamics inapplicable. Accordingly, we propose a novel methodology to study the thermodynamic properties of regular black holes. Thermodynamic quantities must be defined in the full, unconstrained thermodynamic phase space of the underlying singular black holes; only afterward is the constraint imposed to derive the consistent and meaningful thermodynamic quantities of the regular black holes. Crucially, this framework extends beyond regular black holes and applies universally to any black hole with this kind of constraint.