503 research outputs found
Interplay between Quantum Size Effect and Strain Effect on Growth of Nanoscale Metal Thin Film
We develop a theoretical framework to investigate the interplay between
quantum size effect (QSE) and strain effect on the stability of metal
nanofilms. The QSE and strain effect are shown to be coupled through the
concept of "quantum electronic stress. First-principles calculations reveal
large quantum oscillations in the surface stress of metal nanofilms as a
function of film thickness. This adds extrinsically additional strain-coupled
quantum oscillations to surface energy of strained metal nanofilms. Our theory
enables a quantitative estimation of the amount of strain in experimental
samples, and suggests strain be an important factor contributing to the
discrepancies between the existing theories and experiments
Long Range Intrinsic Ferromagnetism in Two Dimensional Materials and Dissipationless Future Technologies
The inherent susceptibility of low-dimensional materials to thermal
fluctuations has long been expected to poses a major challenge to achieving
intrinsic long-range ferromagnetic order in two-dimensional materials. The
recent explosion of interest in atomically thin materials and their assembly
into van der Waals heterostructures has renewed interest in two-dimensional
ferromagnetism, which is interesting from a fundamental scientific point of
view and also offers a missing ingredient necessary for the realization of
spintronic functionality in van der Waals heterostructures. Recently several
atomically thin materials have been shown to be robust ferromagnets. Such
ferromagnetism is thought to be enabled by magneto crystalline anisotropy which
suppresses thermal fluctuations. In this article, we review recent progress in
two-dimensional ferromagnetism in detail and predict new possible
two-dimensional ferromagnetic materials. We also discuss the prospects for
applications of atomically thin ferromagnets in novel dissipationless
electronics, spintronics, and other conventional magnetic technologies.
Particularly atomically thin ferromagnets are promising to realize time
reversal symmetry breaking in two-dimensional topological systems, providing a
platform for electronic devices based on the quantum anomalous Hall Effect
showing dissipationless transport. Our proposed directions will assist the
scientific community to explore novel two-dimensional ferromagnetic families
which can spawn new technologies and further improve the fundamental
understanding of this fascinating area.Comment: To be appear in Applied Physics Review
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