Nonlocal conductance spectroscopy of Andreev bound states in 2DEG-based nanowires*

We present experimental measurements of local and nonlocal tunneling spectroscopy of Andreev bound states in a hybrid superconductor-semiconductor three-terminal device based on a gate-defined InAs two-dimensional electron gas (2DEG) with an epitaxial Al layer. Andreev bound states in a nanowire with 0.6 μm between probes are investigated as a function of parallel magnetic field. At magnetic fields of order 2 T, we observe low-energy Andreev bound states, which oscillate around zero bias as a function of gate voltage, as expected, revealing in the non-local signal the oscillating electron-hole character of the bound state, consistent with theoretical predictions [1,2]. 

 

[1] J. Danon et al, Phys. Rev. Lett. 124, 036801 (2020)

[1] G.C. Ménard et al, Phys. Rev. Lett. 124, 036802 (2020)