Non-identical moiré twins in bilayer graphene.

The superlattice obtained by aligning a monolayer graphene and boron nitride (BN) inherits from the hexagonal lattice a sixty degrees periodicity with the layer alignment. It implies that, in principle, the properties of the heterostructure must be identical for 0° and 60° of layer alignment. Here, we demonstrate, using dynamically rotatable van der Waals heterostructures, that the moiré superlattice formed in a bilayer graphene/BN has different electronic properties at 0° and 60° of alignment.

Helium Ions Put Magnetic Skyrmions on the Track.

Magnetic skyrmions are deemed to be the forerunners of novel spintronic memory and logic devices. While their observation and their current-driven motion at room temperature have been demonstrated, certain issues regarding their nucleation, stability, pinning, and skyrmion Hall effect still need to be overcome to realize functional devices. Here, we demonstrate that focused He-ion-irradiation can be used to create and guide skyrmions in racetracks.

3D superconducting hollow nanowires with tailored diameters grown by focused He beam direct writing.

Currently, the patterning of innovative three-dimensional (3D) nano-objects is required for the development of future advanced electronic components. Helium ion microscopy in combination with a precursor gas can be used for direct writing of three-dimensional nanostructures with a precise control of their geometry, and a significantly higher aspect ratio than other additive manufacturing technologies. We report here on the deposition of 3D hollow tungsten carbide nanowires with tailored diameters by tuning two key growth parameters, namely current and dose of the ion beam.

Three-Dimensional Superconducting Nanohelices Grown by He-Focused-Ion-Beam Direct Writing.

Novel schemes based on the design of complex three-dimensional (3D) nanoscale architectures are required for the development of the next generation of advanced electronic components. He focused-ion-beam (FIB) microscopy in combination with a precursor gas allows one to fabricate 3D nanostructures with an extreme resolution and a considerably higher aspect ratio than FIB-based methods, such as Ga FIB-induced deposition, or other additive manufacturing technologies. In this work, we report the fabrication of 3D tungsten carbide nanohelices with on-demand geometries via controlling key deposition parameters.

Chiral domain walls of MnSn and their memory.

Magnetic domain walls are topological solitons whose internal structure is set by competing energies which sculpt them. In common ferromagnets, domain walls are known to be of either Bloch or Néel types. Little is established in the case of MnSn, a triangular antiferromagnet with a large room-temperature anomalous Hall effect, where domain nucleation is triggered by a well-defined threshold magnetic field.

Vertical Growth of Superconducting Crystalline Hollow Nanowires by He Focused Ion Beam Induced Deposition.

Novel physical properties appear when the size of a superconductor is reduced to the nanoscale, in the range of its superconducting coherence length (ξ). Such nanosuperconductors are being investigated for potential applications in nanoelectronics and quantum computing. The design of three-dimensional nanosuperconductors allows one to conceive novel schemes for such applications.

Fabrication of Ion-Shaped Anisotropic Nanoparticles and their Orientational Imaging by Second-Harmonic Generation Microscopy.

Ion beam shaping is a novel and powerful tool to engineer nanocomposites with effective three-dimensional (3D) architectures. In particular, this technique offers the possibility to precisely control the size, shape and 3D orientation of metallic nanoparticles at the nanometer scale while keeping the particle volume constant. Here, we use swift heavy ions of xenon for irradiation in order to successfully fabricate nanocomposites consisting of anisotropic gold nanoparticle that are oriented in 3D and embedded in silica matrix.

Original electrospun core-shell nanostructured Magnéli titanium oxide fibers and their electrical properties.

A combination of sol-gel chemistry and the electrospinning process leads to unprecedented versatility in the design of nano-Magnéli phases. Adjusting experimental levers provides an efficient route for tuning the composition, the crystal structure, and the nano- and microstructure of titanium sub-oxides, thus paving the way to functional membranes and tissues.

Dimensional crossover in quantum networks: from macroscopic to mesoscopic physics.

We report on magnetoconductance measurements of metallic networks of various sizes ranging from 10 to 10(6) plaquettes, with an anisotropic aspect ratio. Both Altshuler-Aronov-Spivak h/2e periodic oscillations and Aharonov-Bohm h/e periodic oscillations are observed for all networks. For large samples, the amplitude of both oscillations results from the incoherent superposition of contributions of phase coherent regions.

Experimental test of the numerical renormalization-group theory for inelastic scattering from magnetic impurities.

We present measurements of the phase coherence time taupsi in quasi-one-dimensional Au/Fe Kondo wires and compare the temperature dependence taupsi of with a recent theory of inelastic scattering from magnetic impurities [Phys. Rev. Lett.

Switching of magnetization by nonlinear resonance studied in single nanoparticles.

Magnetization reversal in magnetic particles is one of the fundamental issues in magnetic data storage. Technological improvements require the understanding of dynamical magnetization reversal processes at nanosecond time scales. New strategies are needed to overcome current limitations.