Nanosecond stochastic operation in perpendicular superparamagnetic tunnel junctions
arxiv(2024)
摘要
We demonstrate the miniaturization of perpendicularly magnetized
superparamagnetic tunnel junctions (SMTJs) down to 50 nm in diameter. We
experimentally show stochastic reversals in those junctions, with tunable mean
dwell times down to a few nanoseconds through applied magnetic field and
voltage. The mean dwell times measured at negligible bias voltage agree with
our simulations based on Langer's theory. We shed light on an Arrhenius
prefactor τ_0 of a few femtoseconds, implying that the rates of
thermally-activated magnetic transitions exceed the GHz-to-THz limitation of
macrospin models, whereby τ_0∼1 ns. We explain the small prefactor
values by a Meyer-Neldel compensation phenomenon, where the prefactor exhibits
a large entropic contribution with an exponential dependence on the activation
energy. These findings pave the way towards the development of ultrafast,
low-power unconventional computing schemes operating by leveraging thermal
noise in perpendicular SMTJs, which are scalable below 20 nm.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要