Conductance spectroscopy of Andreev bound states in multi-terminal Josephson junctions

Multi-terminal Josephson junctions (JJs) can host unconventional Andreev bound states (ABSs) of which the energy levels depend on multiple superconducting phases. It is interesting that zero-energy ABSs may exist in multi-terminal JJs [1]. A recent report of critical current measurements on multi-terminal JJs implies the existence of multi-terminal ABSs [2]. In addition, we study conductance spectroscopy through quantum point contacts between multi-terminal JJs and normal leads. Device fabrications and phase-dependent conductance on multi-terminal JJs will be discussed.

[Ref. 1] Riwar et al. "Multi-terminal Josephson junctions as topological matter." Nat Commun 7, 11167 (2016).
[Ref. 2] Pankratova, et al. "Multiterminal Josephson Effect." Physical Review X 10.3 (2020): 031051.