论文标题
在超导体 - Quantum dot-percoductor结中的Josephson辐射
Josephson radiation in a superconductor-quantum dot-superconductor junction
论文作者
论文摘要
我们研究了由量子点制成的连接发出的约瑟夫森辐射，该量子点耦合到两个常规超导体。接近共振，颗粒 - 孔对称的Andreev表示，在连接处形成的粒子对称性与铅的超导间隙上方的连续体分离，而它们之间的间隙在费米水平附近打开。在电压偏置下，我们制定了一个随机模型，该模型解释了非绝热过程，该过程改变了安德里夫州的职业。该模型允许计算当前的噪声频谱并确定FANO因子。分析有限频噪声，我们发现该模型可能表现出整数或分数AC Josephson效应，具体取决于Andreev Spectrum中的偏置电压和间隙的大小。我们的结果评估了使用分数Josephson辐射作为拓扑探测的局限性。
We investigate the Josephson radiation emitted by a junction made of a quantum dot coupled to two conventional superconductors. Close to resonance, the particle-hole symmetric Andreev states that form in the junction are detached from the continuum above the superconducting gap in the leads, while a gap between them opens near the Fermi level. Under voltage bias, we formulate a stochastic model that accounts for non-adiabatic processes, which change the occupations of the Andreev states. This model allows calculating the current noise spectrum and determining the Fano factor. Analyzing the finite-frequency noise, we find that the model may exhibit either an integer or a fractional AC Josephson effect, depending on the bias voltage and the size of the gaps in the Andreev spectrum. Our results assess the limitations in using the fractional Josephson radiation as a probe of topology.
