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arXiv 1202.0073cond-mat.supr-con
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超导MoGe纳米线量子相位滑移的开关电流统计定量分析

Quantitative analysis of quantum phase slips in superconducting MoGe nanowires revealed by switching-current statistics

T. Aref, A. Levchenko, V. Vakaryuk, A. Bezryadin

摘要:

我们测量量子和热相位滑移率使用的标准偏差的开关电流在超导纳米线在高偏置电流。我们严格的定量分析提供了坚实的证据,量子相位滑移(QPS)在均匀的纳米线的存在。我们观察到,随着温度降低,热波动冻结在特征交叉温度Tq,低于该温度,开关电流的色散饱和到一个恒定值,表明QPS的存在。交叉温度Tq与临界温度Tc成线性关系,这与宏观量子隧穿理论相一致。我们可以通过施加校准的电压脉冲将线从初始的非晶相原位转换为单晶相。这种技术使我们能够直接探测线电阻、临界温度和形貌对热和量子相位滑移的影响。

英文摘要:

We measure quantum and thermal phase-slip rates using the standard deviation of the switching current in superconducting nanowires at high bias current. Our rigorous quantitative analysis provides firm evidence for the presence of quantum phase slips (QPS) in homogeneous nanowires. We observe that as temperature is lowered, thermal fluctuations freeze at a characteristic crossover temperature Tq, below which the dispersion of the switching current saturates to a constant value, indicating the presence of QPS. The scaling of the crossover temperature Tq with the critical temperature Tc is linear, which is consistent with the theory of macroscopic quantum tunneling. We can convert the wires from the initial amorphous phase to a single crystal phase, in situ, by applying calibrated voltage pulses. This technique allows us to probe directly the effects of the wire resistance, critical temperature and morphology on thermal and quantum phase slips.

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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