Science China Physics, Mechanics & Astronomy最新文献

Transition metal dichalcogenide (TMD) monolayers provide a versatile platform for nanophotonic and optoelectronic devices due to their direct bandgap and strong excitonic response. However, tailoring their emission characteristics beyond the intrinsically narrow excitonic linewidth remains a key challenge. Here, we report a hybrid microcavity platform consisting of a WS₂ monolayer coupled to polystyrene microspheres (PS-MSs) on a gold substrate under continuous-wave excitation. In this system, light emission can be tailored through the interplay between cavity-enhanced local electromagnetic fields and photoinduced changes in the microcavity optical response. At low excitation powers, the emission evolves from neutral-exciton-dominated to trion-dominated photoluminescence with a continuously tunable intensity ratio, reflecting changes in the relative exciton-trion contributions under laser excitation. At higher excitation powers, the system transitions to a broadband-emission regime, which is associated with irradiation-induced modifications of the microcavity optical properties and is further enhanced by the cavity configuration. The incorporation of the WS₂ monolayer is correlated with enhanced broadband emission and improved performance under continuous-wave excitation, while also influencing the interfacial excitonic emission behavior. Furthermore, extending this approach to multiple-microsphere assemblies enables larger-area broadband emission, suggesting the potential scalability of this strategy toward planar white-light sources. These results establish a simple strategy for tailoring light emission in hybrid microcavities and provide insights into cavity-enhanced optical processes in coupled two-dimensional material-polymer systems, with potential applications in integrated photonic devices and broadband light sources.

Gravitational quantum field theory (GQFT) has been proposed as a candidate framework to reconcile general relativity with quantum field theory, and a distinctive imprint on gravitational-wave (GW) polarizations is crucially predicted. While general relativity allows only two tensor modes (+, ×), GQFT additionally favors a massless breathing scalar mode, providing a compelling yet largely unexplored observational target for testing quantum gravity. The central challenge is therefore to assess, in a mission-agnostic manner, how well future space-based interferometers can disentangle and detect these tensor and scalar polarization components across the sky. In this work, we develop a model-independent response formalism for LISA- and Taiji-like detectors by incorporating first-order orbital dynamics in the solar system barycenter frame. This framework yields three key observational consequences: (i) characteristic interference patterns between tensor and scalar modes, (ii) a generalized, model-independent response function for the breathing mode, and (iii) sky-position-dependent strategies that optimize detectability. We further translate the formalism into comprehensive polarization maps that provide complete sky coverage and remain fully compatible with existing mission designs, thereby circumventing the need for challenging direct breathing-mode measurements. Overall, our results deliver practical tools for future data analysis and establish a systematic avenue to test fundamental theories of gravity through their GW polarization fingerprints.

Direct, real-space imaging of spin-wave propagation and wavefronts in magnetic materials is crucial for advancing both fundamental understanding of spin dynamics and the development of functional devices. This, however, remains a significant challenge, especially in materials with complex magnetic characteristics at the nanoscale. Here, we employ scanning nitrogen-vacancy center spectroscopy to achieve visualization of spin waves in two archetypal magnetic films: yttrium-iron-garnet and lanthanum strontium manganese oxide. We reveal a wavelength-dependent spin-wave filtering effect near point-like magnetic scatterers and a modified spin wavefront in antiferromagnetically coupled stripe domains. The spin-wave characteristics are explained using micromagnetic simulations and analytical calculations. These findings point to possible fine control of spin-wave propagation near complex magnetic structures and extend the scope of spin-wave imaging based on nitrogen-vacancy centers beyond uniform magnets.

Quantum effects have been proposed to play functional roles in biological processes such as photosynthetic energy transfer and avian magnetoreception. In photosynthetic light-harvesting complexes, excitation energy transfer can proceed with remarkably high efficiency. With advances in experimental techniques, two-dimensional electronic spectroscopy can reveal dynamic processes such as coherence and coupling within a system, and it plays an important role in studying energy transfer in photosynthesis. On the theory side, methods such as the generalized Bloch-Redfield theory and the hierarchical equations of motion are used to model photosynthetic systems. Quantum simulation has also emerged as a complementary route for investigating photosynthetic dynamics, with implementations on multiple experimental platforms. In recent years, a series of studies has introduced quantum coherence into artificial systems to enhance energy transfer efficiency, laying the groundwork for the design of coherent devices with efficient energy transport. Birds are thought to sense direction by exploiting the weak geomagnetic field through spin-dependent chemical reactions. Theoretical frameworks for animal navigation include magnetite-based mechanisms, magnetoreceptor genes, and the radical-pair mechanism. Quantum simulation of magnetoreception-related spin dynamics has likewise progressed across multiple platforms. Inspired by animal navigation, diverse quantum effects have been applied to improve sensing and to support navigation tasks. This review summarizes recent progress in quantum coherence related to photosynthesis and avian magnetoreception, with emphasis on experimental advances, theoretical methods, quantum simulation, and the design of bioinspired coherent devices.