Modeling of microwave-assisted switching in micron-sized magnetic ellipsoids

Integration and characterization of micron-sized YIG structures with very low Gilbert damping on arbitrary substrates

We present a novel process that allows the transfer of monocrystalline yttrium-iron-garnet microstructures onto virtually any kind of substrate. The process is based on a recently developed method that allows the fabrication of freestanding monocrystalline YIG bridges on gadolinium-gallium-garnet. Here the bridges' spans are detached from the substrate by a dry etching process and immersed in a watery solution. Using drop casting the immersed YIG platelets can be transferred onto the substrate of choice, where the structures finally can be reattached and thus be integrated into complex devices…

Rotational microrheology of Maxwell fluids using micron-sized wires

We demonstrate a simple method for rotational microrheology in complex fluids, using micrometric wires. The three-dimensional rotational Brownian motion of the wires suspended in Maxwell fluids is measured from their projection on the focal plane of a microscope. We analyze the mean-squared angular displacement of the wires of length between 1 and 40 microns. The viscoelastic properties of the suspending fluids are extracted from this analysis and found to be in good agreement with macrorheology data. Viscosities of simple and complex fluids between 0.01 and 30 Pa.s could be measured. As for t…

Magnetic vortex as a ground state for micron-scale antiferromagnetic samples

Here we consider micron-sized samples with any axisymmetric body shape and made with a canted antiferromagnet, like hematite or iron borate. We find that its ground state can be a magnetic vortex with a topologically non-trivial distribution of the sublattice magnetization $\vec{l}$ and planar coreless vortex-like structure for the net magnetization $\vec{M}$. For antiferromagnetic samples in the vortex state, in addition to low-frequency modes, we find high-frequency modes with frequencies over the range of hundreds of gigahertz, including a mode localized in a region of radius $\sim$ 30--40 …

Thermally-Limited Current Carrying Ability of Graphene Nanoribbons

We investigate high-field transport in graphene nanoribbons (GNRs) on SiO2, up to breakdown. The maximum current density is limited by self-heating, but can reach >3 mA/um for GNRs ~15 nm wide. Comparison with larger, micron-sized graphene devices reveals that narrow GNRs benefit from 3D heat spreading into the SiO2, which enables their higher current density. GNRs also benefit from lateral heat flow to the contacts in short devices (< ~0.3 um), which allows extraction of a median GNR thermal conductivity (TC), ~80 W/m/K at 20 C across our samples, dominated by phonons. The TC of GNRs is an or…

从电影到鳞片：yttrium铁石榴石的电子性质和磁化变化

From Film to Flakes: Electronic Properties and Magnetization Variations in Yttrium Iron Garnet

本文比较了类似体材的YIG薄膜和亚微米鳞片的电子和磁性特性，揭示了亚微米尺寸下的独特行为，为鳞片基YIG在紧凑型自旋电子器件中的应用提供了前景。

基于六方氮化硼中VB-量子传感器的亚微米三维磁映射实时ESR追踪

Real-time ESR tracking for sub-micron 3D magnetic mapping with VB- quantum sensors in hexagonal boron nitride

本研究采用六方氮化硼中VB-量子传感器的自旋共振频率追踪技术，实现了亚微米分辨率的三维磁映射，将磁成像采集时间缩短至少一个数量级。