在简短的普通金属/超导体连接处检测双重射击噪声
Nature
|May 16, 2000
概括
这项研究证实,当Cooper对,携带电子的两倍电荷,从超导体发出的时,射击噪声会增加一倍. 这一观察甚至在没有相连贯的情况下也成立,验证了理论预测.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 量子现象是一种量子现象.
背景情况:
- 射击噪声源于电荷载体的离散性质,噪声强度与载体电荷成比例.
- 之前的实验使用了射击噪声来检测分数电荷在分数量子霍尔效应.
- 超导体中的库珀对携带电子的基本电荷的两倍.
研究的目的:
- 通过实验验证库珀对辐射所产生的射击噪声预测的翻倍.
- 调查相连贯在观察这种双电荷噪声特征中的作用.
主要方法:
- 使用了一个短的扩散性普通金属超导体接触.
- 在一系列偏差电流中进行射击噪声测量.
主要成果:
- 观察到枪声的翻倍,与库珀对排放相一致.
- 证实这种效应独立于相位连贯性.
- 验证了双电荷载体射击噪声行为的理论预期.
结论:
- 该实验成功地证明了库珀对预测的射击噪声翻倍.
- 阶段一致性不是观察这种现象的先决条件.
- 这一发现为库珀对的指控提供了进一步的证据,并提供了一种新的检测方法.
更多相关视频
相关概念视频
¹H NMR: Interpreting Distorted and Overlapping Signals
1.3K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.3K
Diamagnetic Shielding of Nuclei: Local Diamagnetic Current
1.3K
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local diamagnetic current arising from circulating sigma-bonding electrons induces a magnetic field, Blocal that opposes the applied magnetic field, B0. The effective magnetic field experienced by these nuclei is given by the difference between the applied and local magnetic fields in a phenomenon called local diamagnetic shielding. Essentially,...
1.3K
¹³C NMR: ¹H–¹³C Decoupling
1.7K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.7K
Double Resonance Techniques: Overview
874
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
874
Metal-Semiconductor Junctions
1.4K
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
1.4K
Biasing of Metal-Semiconductor Junctions
919
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
919


