Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “WIRE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,783 records · Page 99
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Spin-orbit-coupled quantum wires and Majorana fermions on zigzag edges of monolayer transition-metal dichalcogenides

Majoranafermions,quantumparticleswithnon-Abelianexchangestatistics,arenotonlyoffundamentalimportance,butalsobuildingblocksforfault-tolerantquantumcomputation.AlthoughcertainexperimentalbreakthroughsforobservingMajoranafermionshavebeenmaderecently,theirconclusivedetectionisstillchallengingduetothelackofpropermaterialpropertiesoftheunderlinedexperimentalsystems.HereweproposeaplatformforMajoranafermionsbasedonedgestatesofcertainnontopologicaltwo-dimensionalsemiconductorswithstrongspin-orbitcoupling,suchasmonolayergroup-VItransition-metaldichalcogenides(TMDs).Using rst-principlescalculationsandtight-bindingmodeling,weshowthatzigzagedgesofmonolayerTMDcanhostawellisolatedsingleedgebandwithstrongspin-orbit-couplingenergy.Combiningwithproximityinduceds-wavesuperconductivityandin-planemagnetic elds,thezigzagedgesupportsrobusttopologicalMajoranaboundstatesattheedgeends,althoughthetwo-dimensionalbulkitselfisnontopological.

Chu, Rui-Lin↗
DOE OSTI2022

Fragmentation of faceted crystalline wires

The reduction of surface energy is a well-known driving force for the fragmentation of nanowires. Fragmentation can limit the service life of those small low-dimensional building blocks or can be controlled to induce beneficial shape changes. For isotropic surface energy, fragmentation is analogous to the classic Rayleigh-Plateau instability of liquid jets. However, commonly synthesized crystalline nanowires have strongly anisotropic surface energies and exhibit facets coinciding with cusps in the Wulff plot. Depending on growth orientation, different fragmentation behaviors have been seen in nanowires. Using phase-field simulations, we show that fragmentation of faceted nanowires with cubic crystal symmetry may occur by a finite-amplitude nonlinear instability, as opposed to a Rayleigh-Plateau-like linear instability, depending on nanowire growth orientation. Here, we carry out a weakly nonlinear analysis based on sharp interface theory to characterize the faceted nanowire shape corresponding to a surface-energy saddle point. The analysis predicts that the minimum amplitude of a periodic shape perturbation to trigger fragmentation increases with cusp strength but decreases inversely proportionally to the perturbation wavelength for long wavelengths, in good quantitative agreement with phase-field predictions. The results provide the theoretical foundation to predict nanowire stability as a function of length and surface energy in diverse applications.

36 MATERIALS SCIENCE↗