Abstract Magnetic nanoparticles have been proposed as contact-free minimal-background nanobarcodes, and yet it has difficult to rapidly reliably decode them in an assembly. Here, high aspect ratio nanoparticles, or magnetic nanowires (MNWs), are characterized using first-order reversal curves (FORC) investigate quantitative decoding. We synthesized four types of (differing diameter) that might be used for barcoding, identified possible “signature” functions quickly distinguish them. To test...

In heat-assisted magnetic recording, optical energy is transferred to a small spot on the recording media using near field transducer. this study, scattered finite difference time domain simulation used analyze performance of lollipop transducer in heat assisted both patterned FePt and continuous thin film. To represent wear, sharp corners peg are approximated with curved ones, which found narrow track width without excessive loss intensity. Compared media, exhibits higher efficiency better...

Feasibility of heat assisted magnetic recording for granular and bit-patterned media (BPM) is evaluated in the context various noises. Using micromagnetic simulation renormalized cells, we predict that jitter only 0.58 nm at a head speed 10 m/s bilayer structure FeRh/FePt when grain size 3.2 nm, validating possibility 6 Tb/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . We propose new FePt/Cr/X/FePt uses Cr layer to produce an...

Growing uncertainty in design parameters (and therefore, functionality) renders stochastic computing particularly promising, which represents and processes data as quantized probabilities. However, due to the difference representation, integrating conventional memory (designed optimized for non-stochastic computing) systems inevitably incurs a significant conversion overhead. Barely any proposal to-date covers impact. In this paper, first study of its kind best our knowledge, we rethink...

We have investigated the feasibility of BPM for HAMR via Finite Difference Time Domain and atomistic simulation we substantiated 5 Tb/in2 with two filling factors 25% 56% even when maximum on-track bit temperature is below Curie temperature. The success this underheated switching attributed to sufficiently low anisotropy instead reduction gradient in cross-track direction almost doubled if optical head width reduced by half, indicating possibility higher areal densities. Moreover, contrary...

Heat-assisted magnetic recording (HAMR) can support extremely high areal densities based on the thermal stability argument. However, significant challenges remain to reduce switching probability distribution (SPD) improve media SNR. Exchange coupled composite (ECC)-type architectures, such as designs employed in perpendicular media, are being explored for HAMR and show potential promise at reducing SPD. In this article, we propose a new approach design that consisting of an exchange...

We have studied the impact of structural randomness on variation in optical absorption recording grains. Using finite-difference time-domain simulation, we demonstrate that size, shape, and position FePt grain can cause 2%-9% absorption, depending strength randomness. also discussed resulting several design parameters: air gap, average size its standard deviation, permittivity boundaries, seedlayer thickness, aspect ratio random jitter is comparable to experimentally estimated variations...

The Vestibulo-Ocular Reflex (VOR) plays an essential role in the majority of daily activities by keeping images world steady on retina when either environment or body is moving. modeling and identification this system a key diagnosis treatment various diseases lesions, their associated syndromes. Today, clinical protocols incorporate mathematical techniques for testing functionality patients' VORs through analysis responses to stimuli. We have developed new tool simultaneous two modes...

The validity of effective medium theory for modeling nanocomposite thin films interacting with a plasmonic nanoantenna has been investigated using an optical circuit model and finite-difference time-domain simulations. We show that in the regime where size beam generated by is comparable to feature inside film, not valid anymore. demonstrate can cause dramatic error performance analysis applications such as heat assisted magnetic recording work at this regime. Therefore, we develop...

Finite-size scaling is utilized to study the erasure mechanism in heat-assisted magnetic recording (HAMR). Predicted equations are evaluated both numerically and experimentally by using write current-assist percentage (WCAP) method. The method estimates erasing temperature of an external field writing magnetization patterns at different frequencies. In particular, WCAP modeling shows that Curie scales according time scale grain exposed elevated temperature. deviation erase from T <sub...

The grain shape dependence of absorption has been investigated in metal-insulator thin films. We demonstrate that randomness the size and plasmonic particles can lead to Anderson localization polarization modes deep subwavelength regime. These localized contribute significant variation local field. In case nanodevices, effects have by mapping an electrostatic Hamiltonian onto presence a random vector potential. show behavior optical beam be understood terms weighted density depolarization...

Heat assisted magnetic recording (HAMR) has been shown to provide substantial growth in hard disk areal densities compared the conventional perpendicular [1 , 2] . The continued of density capability (ADC) HAMR media relies on grain-size reduction its grains. As we continue reduce grain-size, however, maximum ADC is expected close around ~3 Tbpsi, limited by lowered stability grains [1] Dual layer media, with an exchange break separating two layers distinct Tc was proposed [3] as a design...

Advances in 3D fabrication have afforded new freedoms the design of custom optical elements. We explore a space where refractive index may vary freely with position material by considering applications coherent beam shaping. First, we will describe experimental results used femtosecond laser writing to fabricate GRIN waveguides planar geometry. show 2D device that converts Gaussian flat top one transverse direction, and is single-mode waveguide other. Second, numerical method for designing...

In this paper gradient-index beam shapers are fabricated using the ultrafast laser inscription method. This method enables fabrication of two-dimensional refractive index profiles inside silica glass, resulting in highly robust and compact shapers. The magnitude change can be tailored by adjusting pulse energy, enabling arbitrary to manufactured. process is then demonstrated fabricating planar waveguides with quadratic that predictably resize Gaussian beams. Then a more complex profile...

Heat assisted magnetic recording (HAMR) is a promising approach to increase the areal density beyond 1 Tb/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . In HAMR system, an optical near field transducer (NFT) used locally temperature of media so that writing head can write information on media. Various types NFT designs have been investigated improve efficiency and shape beam However, effects structure performance are not well...

Deep neural networks (DNNs) have been used to investigate geometrical scaling of heat-assisted magnetic recording (HAMR). Our investigation considers areal density capability (ADC) sensitivity with respect distinctive design features. We study HAMR performance by numerical key parameters including thermal profile spot size and reader dimension. DNNs are trained based on a full system model, which includes the writer, reader, channel detector, accelerate ADC optimization through scaling. In...

The eyes play a major role in our everyday activities. Eye movements are controlled by the oculomotor system, which enables us to stay focused on visual targets, switch attention, and compensate for external perturbations. This system's response isolated or vestibular stimuli has been studied decades, but what seems be more critical is know how it would respond combination of these stimuli, because most natural situations, multiple present. It now believed that sensory fusion does not affect...

We used the FDTD simulation to study photon propagation in arrays of plasmonic particles. In such systems, structural randomness can lead localization light deep subwavelength regime, similar Anderson electrons.