Assouline Alexandre, Feuillet-Palma Cheryl, Zimmers Alexandre, Aubin Hervé, Aprili Marco, Harmand Jean-Christophe
LPEM, ESPCI Paris, PSL Research University; CNRS; Sorbonne Universités, UPMC University of Paris 6, 10 rue Vauquelin, F-75005 Paris, France.
Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, University Paris-Saclay, 91405 Orsay Cedex, France.
Phys Rev Lett. 2017 Sep 1;119(9):097701. doi: 10.1103/PhysRevLett.119.097701. Epub 2017 Aug 31.
We present a study of Andreev quantum dots fabricated with small-diameter (30 nm) Si-doped InAs nanowires where the Fermi level can be tuned across a mobility edge separating localized states from delocalized states. The transition to the insulating phase is identified by a drop in the amplitude and width of the excited levels and is found to have remarkable consequences on the spectrum of superconducting subgap resonances. While at deeply localized levels only quasiparticle cotunneling is observed, for slightly delocalized levels Shiba bound states form and a parity-changing quantum phase transition is identified by a crossing of the bound states at zero energy. Finally, in the metallic regime, single Andreev resonances are observed.
我们展示了一项关于用小直径（30纳米）硅掺杂砷化铟纳米线制造的安德列夫量子点的研究，其中费米能级可以在将局域态与非局域态分开的迁移率边缘上进行调节。向绝缘相的转变通过激发能级的幅度和宽度下降来识别，并且发现这对超导亚能隙共振光谱有显著影响。虽然在深度局域能级仅观察到准粒子共隧穿，但对于略微非局域的能级，形成了芝田束缚态，并且通过零能量处束缚态的交叉识别出奇偶性改变的量子相变。最后，在金属 regime中，观察到单安德列夫共振。
