It is commonly accepted that the isomerization process primarily occurs in lowly charged molecular states, while highly charged states typically favor a direct fragmentation pathway through Coulomb repulsion. In the c...
详细信息
It is commonly accepted that the isomerization process primarily occurs in lowly charged molecular states, while highly charged states typically favor a direct fragmentation pathway through Coulomb repulsion. In the current experiment with an intense 800-nm laser field, a three-body isomerization pathway leading to intermediate O22+ formation and subsequent dissociation is observed in highly excited states of CO23+. It is confirmed by the calculated potential energy curves that CO23+ molecular ions in highly excited states with a linear geometry could transition through conical intersections into low-lying states with a bond angle around 70∘ (e.g., 62A1→12A1, 102B1→12B1), finally leading to oxygen molecule ions formation via isomerization. The present findings demonstrate that isomerization-induced change in molecular structures is a universal and nonnegligible phenomenon, even in triply charged molecular ions, providing insights into the photoinduced ultrafast processes in Earth's primitive atmosphere and benefit the understanding of CO2-dominated planetary atmospheres.
We investigate the statistical properties of cosmic baryon fluid in the nonlinear regime, which is crucial for understanding the large-scale structure formation of the Universe. With the hydrodynamic simulation sample...
详细信息
We investigate the statistical properties of cosmic baryon fluid in the nonlinear regime, which is crucial for understanding the large-scale structure formation of the Universe. With the hydrodynamic simulation sample of the Universe in the cold dark matter model with a cosmological constant, we show that the intermittency of the velocity field of cosmic baryon fluid at redshift z=0 in the scale range from the Jeans length to about 16 h−1 Mpc can be extremely well described by She-Leveque’s universal scaling formula. The baryon fluid also possesses the following features: (1) for volume weight statistics, the dissipative structures are dominated by sheets, and (2) the relation between the intensities of fluctuations is hierarchical. These results imply that the evolution of highly evolved cosmic baryon fluid is similar to a fully developed turbulence.
We report on strain engineering of superconductivity in RuO2 single-crystal films, which are epitaxially grown on rutile TiO2 and MgF2 substrates with various crystal orientations. Systematic mappings between the supe...
详细信息
We report on strain engineering of superconductivity in RuO2 single-crystal films, which are epitaxially grown on rutile TiO2 and MgF2 substrates with various crystal orientations. Systematic mappings between the superconducting transition temperature and the lattice parameters reveal that shortening of specific ruthenium–oxygen bonds is a common feature among the superconducting RuO2 films. Ab initio calculations of electronic and phononic structures for the strained RuO2 films suggest the importance of soft phonon modes for emergence of the superconductivity. The findings indicate that simple transition metal oxides such as those with a rutile structure may be suitable for further exploring superconductivity by controlling phonon modes through the epitaxial strain.
Future-oriented Science&technology(S&T)Strategies trigger the innovative developments of advanced materials,providing an envision to the significant progress of leading-/cutting-edge science,engineering,and te...
详细信息
Future-oriented Science&technology(S&T)Strategies trigger the innovative developments of advanced materials,providing an envision to the significant progress of leading-/cutting-edge science,engineering,and technologies for the next few *** by Made in China 2025 and New Material Power Strategy by 2035,several key viewpoints about automated research workflows for accelerated discovery and smart manufacturing of advanced materials in terms of AI for Science and main respective of big data,database,standards,and ecosys-tems are *** to classical toolkits at various spatial and temporal scales,AI-based toolkits and AI-enabled computations for material design are compared,highlighting the dominant role of the AI agent *** recent developed ProME platform together with its functions is introduced briefly.A case study of AI agent assistant welding is presented,which is consisted of the large language model,auto-coding via AI agent,image processing,image mosaic,and machine learning for welding defect ***,more duties are called to educate the next generation workforce with creative minds and *** is believed that the transformation of knowledge-enabled data-driven integrated computational material engineering era to AI^(+) era promotes the transformation of smart design and manufacturing paradigm from“designing the materials”to“designing with materials.”
We have investigated the magnetic anisotropies of doped manganite materials in epitaxial thin film and single crystal form. Structural characterization, including x-ray diffraction, Rudierford backscattering spectrosc...
We have investigated the magnetic anisotropies of doped manganite materials in epitaxial thin film and single crystal form. Structural characterization, including x-ray diffraction, Rudierford backscattering spectroscopy and atomic force misocroscopy, indicate that our epitaxial films arc single crystalline and have excellent crystallinity. Since lattice distortions greatly affect the magnetic and transport properties of this family of materials, it is not surprising to find the profound effect of strain in films due to the lattice mismatch between the substrate and film. Magnetic anisotropy results of single crystals, subject to no external stress, is compared to those of epitaxial films.
The spontaneous emission spectrum of a multilevel atom or molecule with nonreciprocal transition is investigated. It is shown that the nonreciprocal transition can lead to the elimination of a spectral line in the spo...
详细信息
The spontaneous emission spectrum of a multilevel atom or molecule with nonreciprocal transition is investigated. It is shown that the nonreciprocal transition can lead to the elimination of a spectral line in the spontaneous emission spectrum. As an application, we show that nonreciprocal transition arises from the phase-related driving fields in chiral molecules with cyclic three-level transitions, and the elimination of a spectral line induced by nonreciprocal transition provides us a method to determine the enantiomeric excess for the chiral molecules without requiring the enantio-pure samples.
Two- and three-dimensional Kitaev magnets are prototypical frustrated quantum spin systems, in which the original spin degrees of freedom fractionalize into Majorana fermions and a Z2 gauge field—a purely local pheno...
详细信息
Two- and three-dimensional Kitaev magnets are prototypical frustrated quantum spin systems, in which the original spin degrees of freedom fractionalize into Majorana fermions and a Z2 gauge field—a purely local phenomenon that reveals itself as a thermodynamic crossover at a temperature scale set by the strength of the bond-directional interactions. For conventional Kitaev magnets, the low-temperature thermodynamics reveals a second transition at which the Z2 gauge field orders and the system enters a spin-liquid ground state. Here, we discuss an explicit example that goes beyond this paradigmatic scenario—the Z2 gauge field is found to be subject to geometric frustration, the thermal ordering transition is suppressed, and an extensive residual entropy arises. Deep in the quantum regime, at temperatures of the order of one per mil of the interaction strength, the degeneracy in the gauge sector is lifted by a subtle interplay between the gauge field and the Majorana fermions, resulting in the formation of a Majorana metal. We discuss the thermodynamic signatures of this physics obtained from large-scale, sign-free quantum Monte Carlo simulations.
The ever increasing level of control in the fabrication of graphene/hexagonal boron nitride (h-BN) lateral heterostructures makes it promising for material realization of exotic electronic and spintronic properties of...
详细信息
The ever increasing level of control in the fabrication of graphene/hexagonal boron nitride (h-BN) lateral heterostructures makes it promising for material realization of exotic electronic and spintronic properties of graphene. Yet recent first-principles studies have revealed that the pronounced half-metallicity expected for electrically biased freestanding graphene nanoribbons is severely suppressed when the lateral heterostructures are orientationally aligned. By properly tailoring the orientational misalignment between zigzag graphene and chiral h-BN nanoribbons, here we show that the half-metallicity can be substantially enhanced from the aligned case, back to be comparable in magnitude with the freestanding case. In addition, the strain energy accumulation in such misaligned heterojunctions is significantly diminished, favoring physical realization of such structures. The restored half-metallicity is largely attributed to the recovered superexchange interaction between the electrons at the opposite heterojunction interfaces. The present findings may have important implications in the development of graphene-based spintronics.
For dark compact object such as black hole or wormhole, a shadow has long been thought to come from the outermost unstable photon sphere (region). However, by considering the thin-shell wormhole model, we identify a n...
详细信息
暂无评论