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Magnetic phenomena are ubiquitous in nature and indispensable for modern science and technology, but it is notoriously difficult to change the magnetic order of a material in a rapid way. However, if a thin nickel film is subjected to ultrashort laser pulses, it loses its magnetic order almost completely within femtosecond timescales 1 . This phenomenon is widespread 2 – 7 and offers opportunities for rapid information processing 8 – 11 or ultrafast spintronics at frequencies approaching those of light 8 , 9 , 12 . Consequently, the physics of ultrafast demagnetization is central to modern materials research 1 – 7 , 13 – 28 , but a crucial question has remained elusive: if a material loses its magnetization within mere femtoseconds, where is the missing angular momentum in such a short time? Here we use ultrafast electron diffraction to reveal in nickel an almost instantaneous, long-lasting, non-equilibrium population of anisotropic high-frequency phonons that appear within 150–750 fs. The anisotropy plane is perpendicular to the direction of the initial magnetization and the atomic oscillation amplitude is 2 pm. We explain these observations by means of circularly polarized phonons that quickly absorb the angular momentum of the spin system before macroscopic sample rotation. The time that is needed for demagnetization is related to the time it takes to accelerate the atoms. These results provide an atomistic picture of the Einstein–de Haas effect and signify the general importance of polarized phonons for non-equilibrium dynamics and phase transitions. Ultrafast electron diffraction is used here to reveal in nickel an almost instantaneous, long-lasting population of anisotropic phonons with angular momentum.

Resolving the fundamental carrier dynamics induced in solids by strong electric fields is essential for future applications, ranging from nanoscale transistors1,2 to high-speed electro-optical switches3. How fast and at what rate can electrons be injected into the conduction band of a solid? Here, we investigate the sub-femtosecond response of GaAs induced by resonant intense near-infrared laser pulses using attosecond transient absorption spectroscopy. In particular, we unravel the distinct role of intra- versus interband transitions. Surprisingly, we found that despite the resonant driving laser, the optical response during the light–matter interaction is dominated by intraband motion. Furthermore, we observed that the coupling between the two mechanisms results in a significant enhancement of the carrier injection from the valence into the conduction band. This is especially unexpected as the intraband mechanism itself can accelerate carriers only within the same band. This physical phenomenon could be used to control ultrafast carrier excitation and boost injection rates in electronic switches in the petahertz regime.

Transition metals, with their densely confined and strongly coupled valence electrons, are key constituents of many materials with unconventional properties1, such as high-temperature superconductors, Mott insulators and transition metal dichalcogenides2. Strong interaction offers a fast and efficient lever to manipulate electron properties with light, creating promising potential for next-generation electronics3–6. However, the underlying dynamics is a hard-to-understand, fast and intricate interplay of polarization and screening effects, which are hidden below the femtosecond timescale of electronic thermalization that follows photoexcitation7. Here, we investigate the many-body electron dynamics in transition metals before thermalization sets in. We combine the sensitivity of intra-shell transitions to screening effects8 with attosecond time resolution to uncover the interplay of photo-absorption and screening. First-principles time-dependent calculations allow us to assign our experimental observations to ultrafast electronic localization on d orbitals. The latter modifies the electronic structure as well as the collective dynamic response of the system on a timescale much faster than the light-field cycle. Our results demonstrate a possibility for steering the electronic properties of solids before electron thermalization. We anticipate that our study may facilitate further investigations of electronic phase transitions, laser–metal interactions and photo-absorption in correlated-electron systems on their natural timescales.

Short, intense laser pulses can be used to access the transition regime between classical and quantum optical responses in dielectrics. In this regime, the relative roles of inter- and intraband light-driven electronic transitions remain uncertain. We applied attosecond transient absorption spectroscopy to investigate the interaction between polycrystalline diamond and a few-femtosecond infrared pulse with intensity below the critical intensity of optical breakdown. Ab initio time-dependent density functional theory calculations, in tandem with a two-band parabolic model, accounted for the experimental results in the framework of the dynamical Franz-Keldysh effect and identified infrared induction of intraband currents as the main physical mechanism responsible for the observations.

Chiral effects originate from the lack of inversion symmetry within the lattice unit cell or sample’s shape. Being mapped onto magnetic ordering, chirality enables topologically non-trivial textures with a given handedness. Here, we demonstrate the existence of a static 3D texture characterized by two magnetochiral parameters being magnetic helicity of the vortex and geometrical chirality of the core string itself in geometrically curved asymmetric permalloy cap with a size of 80 nm and a vortex ground state. We experimentally validate the nonlocal chiral symmetry breaking effect in this object, which leads to the geometric deformation of the vortex string into a helix with curvature 3 μm −1 and torsion 11 μm −1 . The geometric chirality of the vortex string is determined by the magnetic helicity of the vortex texture, constituting coupling of two chiral parameters within the same texture. Beyond the vortex state, we anticipate that complex curvilinear objects hosting 3D magnetic textures like curved skyrmion tubes and hopfions can be characterized by multiple coupled magnetochiral parameters, that influence their statics and field- or current-driven dynamics for spin-orbitronics and magnonics. Chiral interactions in magnetic systems enable topologically nontrivial magnetic textures, most notably topological solitons such as skyrmions. Here Volkov et al study the magneto-chiral interactions in a small asymmetric magnetic cap, and show how the geometric asymmetry influence the chiral spin- textures.

We employ alternating magnetic fields (AMF) to drive magnetic fillers actively and guide the formation and self-healing of percolation networks. Relying on AMF, we fabricate printable magnetoresistive sensors revealing an enhancement in sensitivity and figure of merit of more than one and two orders of magnitude relative to previous reports. These sensors display low noise, high resolution, and are readily processable using various printing techniques that can be applied to different substrates. The AMF-mediated self-healing has six characteristics: 100% performance recovery; repeatable healing over multiple cycles; room-temperature operation; healing in seconds; no need for manual reassembly; humidity insensitivity. It is found that the above advantages arise from the AMF-induced attraction of magnetic microparticles and the determinative oscillation that work synergistically to improve the quantity and quality of filler contacts. By virtue of these advantages, the AMF-mediated sensors are used in safety application, medical therapy, and human-machine interfaces for augmented reality. Flexible magnetic sensors with high sensitivity have a wide variety of medical and industrial uses, however, making such sensors robust and flexible at the same time can be challenging. Here, the authors demonstrate a high sensitivity flexible magnetic sensor that exhibits self-healing under an applied alternative magnetic field, with complete performance recovery.

Additive nanotechnology enable curvilinear and three-dimensional (3D) magnetic architectures with tunable topology and functionalities surpassing their planar counterparts. Here, we experimentally reveal that 3D soft magnetic wireframe structures resemble compact manifolds and accommodate magnetic textures of high order vorticity determined by the Euler characteristic, χ . We demonstrate that self-standing magnetic tetrapods (homeomorphic to a sphere; χ  = + 2) support six surface topological solitons, namely four vortices and two antivortices, with a total vorticity of + 2 equal to its Euler characteristic. Alternatively, wireframe structures with one loop (homeomorphic to a torus; χ  = 0) possess equal number of vortices and antivortices, which is relevant for spin-wave splitters and 3D magnonics. Subsequent introduction of n holes into the wireframe geometry (homeomorphic to an n -torus; χ  < 0) enables the accommodation of a virtually unlimited number of antivortices, which suggests their usefulness for non-conventional (e.g., reservoir) computation. Furthermore, complex stray-field topologies around these objects are of interest for superconducting electronics, particle trapping and biomedical applications. The spin texture of a magnetic system can host a variety of topological spin textures, the most famous of these being skyrmions. Here, Volkov et al demonstrate higher order vorticity in magnetic wireframe nanostructures and introduce a general protocol for the creation of arbitrary numbers of vortices and antivortices in such wireframe structures.

Background Non-small-cell lung cancer (NSCLC) exhibits variable outcomes and remains a leading cause of cancer-related mortality, despite advances in immunotherapy. This study aimed to develop a prognostic model using real-world data (RWD) to stratify patients by survival outcomes and evaluate the benefit of immunotherapy across risk groups. Methods A retrospective cohort of 270 patients with NSCLC (2015–2024) treated with chemotherapy alone (54%) or chemoimmunotherapy (46%) was analyzed. Clinical, laboratory (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], monocyte-to-lymphocyte ratio [MLR]), and histopathological data were collected. Multivariate Cox regression identified prognostic factors for overall survival (OS) and validated them via bootstrapping. Results The cohort (median age, 65; 78% male) had a median OS of 11.2 months and a median progression-free survival (PFS) of 7.7 months. The final prognostic model incorporated histology (adenocarcinoma vs. large cell/squamous cell carcinoma/rare subtypes: HR = 1.6–2.03), recurrence state (HR = 0.51), and NLR (HR = 1.13). Patients were stratified into low- (median OS = 14.6 months) and high-risk (median OS = 9.6 months; p <  0.001) groups. Immunotherapy significantly increased PFS in low-risk patients (12.2 vs. 7.1 months, p =  0.002) and showed an increasing trend in OS (16.9 vs. 11.3 months, p =  0.12). High-risk patients derived no OS/PFS benefit ( p  ≥ 0.56). Conclusion This RWD-derived prognostic model effectively stratifies NSCLC patients into distinct risk groups. Immunotherapy-chemotherapy provided meaningful PFS improvement in low-risk patients but minimal benefit in high-risk subgroups, underscoring the need for tailored therapeutic strategies.

The widths of the decays τ → K - K + K - ν τ and τ → K - K 0 K ¯ 0 ν τ are calculated in the U ( 3 ) × U ( 3 ) chiral quark NJL model. Four channels are considered: contact, axial vector, vector, and pseudoscalar channels. It is shown that the dominant contribution is given by the axial vector channel with an intermediate ϕ meson. The results obtained are in satisfactory agreement with the experimental data.

Crystals with broken inversion symmetry can host fundamentally appealing and technologically relevant periodical or localized chiral magnetic textures. The type of the texture as well as its magnetochiral properties are determined by the intrinsic Dzyaloshinskii-Moriya interaction (DMI), which is a material property and can hardly be changed. Here we put forth a method to create new artificial chiral nanoscale objects with tunable magnetochiral properties from standard magnetic materials by using geometrical manipulations. We introduce a mesoscale Dzyaloshinskii-Moriya interaction that combines the intrinsic spin-orbit and extrinsic curvature-driven DMI terms and depends both on the material and geometrical parameters. The vector of the mesoscale DMI determines magnetochiral properties of any curved magnetic system with broken inversion symmetry. The strength and orientation of this vector can be changed by properly choosing the geometry. For a specific example of nanosized magnetic helix, the same material system with different geometrical parameters can acquire one of three zero-temperature magnetic phases, namely, phase with a quasitangential magnetization state, phase with a periodical state and one intermediate phase with a periodical domain wall state. Our approach paves the way towards the realization of a new class of nanoscale spintronic and spinorbitronic devices with the geometrically tunable magnetochirality.