Tunneling Spectroscopy of Andreev Energy Levels in a Quantum Dot Coupled to a Superconductor
Tunneling Spectroscopy of Andreev Energy Levels in a Quantum Dot Coupled to a Superconductor
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DOI：
10.1103/physrevlett.104.076805
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发表时间：
2010-02-19
影响因子：
8.6
通讯作者：
Tarucha, S.
中科院分区：
文献类型：
--
作者：
Deacon, R. S.;Tanaka, Y.;Tarucha, S.
量子点与BCS型超导储层的耦合导致了一个有趣的系统，其中低能物理由两个不同相（单线态和双线态）的相互作用决定。在这封信中，我们表明，安德烈耶夫能级的光谱，捕获的两个阶段的属性，可以检测到在运输测量与量子点强耦合到超导铅和弱耦合到正常的金属铅。我们观察到BCS单重态和简并磁二重态之间的相变时，量子点化学势与静电门调谐，在良好的定性与数值重整化群计算。
The coupling of a quantum dot with a BCS-type superconducting reservoir results in an intriguing system where low energy physics is governed by the interplay of two distinct phases, singlet and doublet. In this Letter we show that the spectrum of Andreev energy levels, which capture the properties of the two phases, can be detected in transport measurements with a quantum dot strongly coupled to a superconducting lead and weakly coupled to a normal metal lead. We observe phase transitions between BCS singlet and degenerate magnetic doublet states when the quantum dot chemical potential is tuned with an electrostatic gate, in good qualitative agreement with numerical renormalization group calculations.