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

Abstract

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. Our results show the smallest and highest-densely packed nanohelix ever fabricated so far, with dimensions of 100 nm in diameter and aspect ratio up to 65. These nanohelices become superconducting at 7 K and show a large critical magnetic field and critical current density. In addition, given its helical 3D geometry, fingerprints of vortex and phase-slip patterns are experimentally identified and supported by numerical simulations based on the time-dependent Ginzburg–Landau equation. These results can be understood by the helical geometry that induces specific superconducting properties and paves the way for future electronic components, such as sensors, energy storage elements, and nanoantennas, based on 3D compact nanosuperconductors.

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

“…Nowadays, research on manufacturing highly energy-efficient three-dimensional (3D) structures [13] is critical for the development of future electronics. However, when approaching the nanometer-scale, the number of works on real 3D nano-superconductors [14][15][16][17][18][19] decreases dramatically, mostly due to the complex fabrication and characterization. A technique successfully utilized for fabricating 3D nano-objects is direct writing by a focused beam of positively charged particles, the so-called focused-ion-beam induced deposition (FIBID) [20].…”

Temperature-Dependent Growth Characteristics of Nb- and CoFe-Based Nanostructures by Direct-Write Using Focused Electron Beam-Induced Deposition

“…Direct-write nano-fabrication by focused electron and ion beam-induced deposition (FEBID/FIBID) has become one of the most promising approaches for the realization of two-and three-dimensional (3D) functional structures with particular relevance for the fields of nano-magnetism [1][2][3][4], nano-optics [5,6], and superconductivity of nanostructures [7,8]. This is due to essentially two important advantages that FEBID/FIBID have as compared to other technologies [9], which are their applicability on virtually any surface and the flexibility to fabricate wireframe- [3] as well as sheet-like [10] structures with sub-100 nm resolution.…”

“…Over the last few years, this has led to the evolution of a simulation-guided 3D computer aided design (CAD) approach which was pioneered by Fowlkes and collaborators [11] and has been further developed towards a reliable instrument for 3D nano-fabrication even of complex nano-architectures, as was recently reviewed by Winkler et al [12]. For the fields of 3D nano-magnetism and nano-superconductivity, the precursors Co 2 (CO) 8 [1], Fe 2 (CO) 9 [13], HCo 3 Fe(CO) 12 [3] (FEBID), W(CO) 6 [14], and Nb(NMe 3 ) 2 (N-t-Bu) [7] (FIBID) have been used and proven to be particularly suited. With a view to the simulation-guided 3D CAD approach to nano-fabrication which uses the continuum model of FEBID/FIBID growth, a set of simulation parameters is required; see Reference [15] for a recent review.…”

2D Manipulation of Nanoobjects by Perpendicular Electric Fields: Implications for Nanofabrication

“…By applying successively E1, E2, -E1 and -E2 we have moved a 2D negative island along a closed loop, as shown by the movie available in the supporting information and summarized in gure 3. The large zone in the center has dark and bright areas, corresponding to atomically at regions with dimer rows oriented along the [110] and the [1][2][3][4][5][6][7][8][9][10] directions alternatively in successive terraces (the dimer rows are schematically represented in gure 3a with three parallel white or black lines). The small bright ellipse in the center is a 2D one-atom-deep hole inside the elliptical dark terrace that is in turn one-atom lower than the bright larger region around it.…”

“…For instance, top-down approaches are used to directly fabricate nanostructures at dened positions 6 .…”