在超薄纳米线中量子抑制超导性
1Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA. alexey@rsj.harvard.edu
Nature
|May 9, 2000
概括
超薄电线的超导性取决于电阻. 低于库珀对 (Rq) 量子电阻的正常状态电阻 (R(N)) 的电线仍然是超导,而高于它的电线由于量子相位滑动而变得绝缘.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 纳米技术 纳米技术
背景情况:
- 超导对于电子来说至关重要,但其微型化的极限是未知的.
- 超导体中的电阻可能来自热激活或量子相位滑动.
- 量子相位滑动可能会破坏超薄电线中的超导性.
研究的目的:
- 为了确定超薄电线中的超导极限.
- 为了确定狭窄的超导电线中限制超导性的因素.
- 为了研究量子相位滑动在超薄超导电路中的作用.
主要方法:
- 使用涂有Mo-Ge合金的碳纳米管制造超薄超导纳米线 (<或=10nm).
- 这些超薄纳米线上的电阻测量.
- 对库珀对 (Rq) 的常态电阻 (R(N)) 和量子电阻之间的关系进行分析.
主要成果:
- 纳米线表现出超导或绝缘的行为.
- 当R(N) < Rq时,超导性被保留,因为强阻尼禁止了量子相位滑坡道.
- 对于R(N) > Rq,观察到一个绝缘状态,归因于量子相位滑转扩散和库珀对局部化.
结论:
- 该比率R (N) /Rq决定了超薄电线是否保持超导或变得绝缘.
- 量子相位滑动对于确定狭窄电线的超导极限至关重要.
- 这一发现对超导电子设备的微型化有影响.
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