Nanolithography by non-contact AFM induced local oxidation : Fabrication of tunneling barriers suitable for single electron devices

B. Irmer; M. Kehrle; H. Lorenz; J. P. Kotthaus

Home/Archive/arXiv

arXiv · cond-mat/9805350

Nanolithography by non-contact AFM induced local oxidation : Fabrication of tunneling barriers suitable for single electron devices

B. Irmer·M. Kehrle·H. Lorenz·J. P. Kotthaus

View original source ↗Read source document ↗Export metadata ↓

Abstract

We study local oxidation induced by dynamic atomic force microscopy (AFM), commonly called TappingMode AFM. This minimizes the field induced forces, which cause the tip to blunt, and enables us to use very fine tips. We are able to fabricate Ti/TiOx line grids with 18 nm period and well defined isolating barriers as small as 15 nm. These junctions show a non-linear current-voltage characteristic and an exponential dependence of the conductance on the oxide width, indicating tunneling as the dominant conduction mechanism. From the conductance - barrier width dependence we derive a barrier height of 178 meV. Numerical calculations of the lateral field distribution for different tip geometries allow to design the optimum tip for the most localised electric field. The electron-beam-deposition (EBD) technique makes it possible to actually produce tips of the desired geometry.

Explore related subjects

cond-mat.mes-hall

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

B. Irmer, M. Kehrle, H. Lorenz, J. P. Kotthaus. 1998-05-27. Nanolithography by non-contact AFM induced local oxidation : Fabrication of tunneling barriers suitable for single electron devices. https://arxiv.org/abs/cond-mat/9805350

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Photoinduced topological phase transition in monolayer 1T$^\prime$-MoS$_2$

We investigate the systematic competition between perpendicular electric field and circularly polarized light in nonequilibrium topological phases of monolayer 1T$^\prime$--MoS$_2$ using a low-energy $k\!\cdot\!p$ Hamiltonian and Floquet theory. The off-resonant field generates spin- and valley-dependent mass corrections that reshape the Berry curvature (BC) and shift the conditions for band inversion. By evaluating the quasienergy bands, BC, and spin- valley-resolved Chern numbers, we identify a sequence of light and electric field controlled topological transitions by gap closing. Depending on the Floquet coupling strength and the electric-field parameter, the system evolves between the equilibrium quantum spin Hall (QSH) state and a set of driven phases including spin-polarized quantum Hall insulator (S-QHI), band insulator (BI) and photo-induced quantum Hall insulator (P-QHI) regimes. The results establish 1T$^\prime$--MoS$_2$ as a tunable platform where circular driving selectively manipulates spin and valley degrees of freedom, enabling controlled access to non-equilibrium topological phases in transition metal dichalcogenides (TMDs).

cond-mat.mes-hall↗

arXiv2026

Engineering Fractional Topological Superconductors: Numerical Bogoliubov-de Gennes Analysis for Parafermion Realization in FCI-Superconductor Heterostructures

We propose a pathway to engineer Z3 parafermion zero modes in fractional Chern insulator-superconductor heterostructures. Using numerical Bogoliubov-de Gennes calculations and edge-theory analysis, we demonstrate how realistic materials such as MoTe2/NbSe2 can host parafermionic excitations with experimentally accessible signatures, including fractional Josephson effects, localized zero modes, interferometry, and thermal transport. Our work outlines concrete strategies for experimentally accessing parafermionic excitations in FCI-superconductor heterostructures.

cond-mat.mes-hall↗

arXiv2026

Disentangling Spin Pumping and Two-Magnon Scattering Contributions to Gilbert Damping in YIG/V Bilayers

In this work, we investigate the magnetic damping and spin pumping response of YIG-based bilayers incorporating vanadium (V) as the normal metal layer via broadband ferromagnetic resonance (FMR) measurements as a function of YIG thickness. We show that the apparent enhancement of the Gilbert damping in YIG/V bilayers cannot be solely attributed to spin pumping. Instead, two-magnon scattering (TMS) plays a dominant role in governing the thickness dependence of the damping in the nanometer regime. By applying a thickness-dependent damping model that accounts for both spin pumping and two-magnon scattering contributions, we successfully disentangle the different relaxation contributions. Our analysis reveals that neglecting two-magnon scattering leads to an overestimation of the spin-pumping contribution and consequently to unphysically large values of the effective spin-mixing conductance. After isolating the intrinsic spin pumping contribution, we extract a thickness-independent effective spin-mixing conductance of $g^{\uparrow\downarrow}_{\mathrm{eff}} = 1.33 \times 10^{18}~\mathrm{m^{-2}}$. These findings provide a more accurate framework for quantifying spin transport parameters in FM/HM systems and emphasize the necessity of accounting for extrinsic damping mechanisms when interpreting spin pumping and inverse spin Hall effect experiments.

cond-mat.mes-hall↗