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arXiv 0904.4432cond-mat.supr-con
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电流偏置纳米线中相位滑移串的随机动力学和超导-电阻开关

Stochastic dynamics of phase-slip trains and superconductive-resistive switching in current-biased nanowires

David Pekker, Nayana Shah, Mitrabhanu Sahu, Alexey Bezryadin, Paul M. Goldbart

摘要:

碳纳米管模板法制备的超导纳米线可用于实现和研究准一维超导体。然而,这些纳米线的线性电阻的测量在确定量子和热的相滑移波动的低温行为方面一直是不确定的。因此,我们的动机是研究电流偏置纳米线的非线性电流-电压特性和超导电阻开关的随机动力学,作为探测相位滑移事件的一种方式。特别是,我们解决的问题:可以一个单一的相位滑移事件发生在某处沿电线-在此期间,序参数波动为零-诱导开关,通过局部加热它的原因?我们探索这一点和相关的问题,通过构建一个随机模型的时间演变的温度在纳米线的两端保持在一个固定的温度。我们推导出相应的主方程作为工具,用于评估和分析在给定的电流值的平均开关时间。该模型表明,虽然在一般情况下,几个相位滑移事件是必要的,以诱导开关通过热失控,确实有一个制度的温度和电流中,一个单一的事件是足够的。我们进行了详细的比较的结果与实验测量的开关电流的分布的模型,并提供了一个解释的反直观的加宽的分布宽度,观察到的温度降低。此外,我们确定了一个制度,在该制度中的实验是探测个人的相位滑移事件,从而提供了一种方法,探索纳米级量子隧穿的超导序参量的物理。

英文摘要:

Superconducting nanowires fabricated via carbon-nanotube-templating can be used to realize and study quasi-one-dimensional superconductors. However, measurement of the linear resistance of these nanowires have been inconclusive in determining the low-temperature behavior of phase-slip fluctuations, both quantal and thermal. Thus, we are motivated to study the nonlinear current-voltage characteristics in current-biased nanowires and the stochastic dynamics of superconductive-resistive switching, as a way of probing phase-slip events. In particular, we address the question: Can a single phase-slip event occurring somewhere along the wire--during which the order-parameter fluctuates to zero--induce switching, via the local heating it causes? We explore this and related issues by constructing a stochastic model for the time-evolution of the temperature in a nanowire whose ends are maintained at a fixed temperature. We derive the corresponding master equation as tool for evaluating and analyzing the mean switching time at a given value of current. The model indicates that although, in general, several phase-slip events are necessary to induce switching via a thermal runaway, there is indeed a regime of temperatures and currents in which a single event is sufficient. We carry out a detailed comparison of the results of the model with experimental measurements of the distribution of switching currents, and provide an explanation for the counter-intuitive broadening of the distribution width that is observed upon lowering the temperature. Moreover, we identify a regime in which the experiments are probing individual phase-slip events, and thus offer a way for exploring the physics of nanoscale quantum tunneling of the superconducting order parameter.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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