The Andreev bound state (ABS) spectra of Multi-terminal Josephson junctions (MTJJs) can form an artificial band structure in arbitrary dimensions. This ABS spectra is predicted to host topologically protected Weyl nodes and higher order Chern numbers [1,2]. The detection of these states require that the number of conductance modes hosted by the central scttering region is close to unity [3,4]. In our recent work [5], we have demonstrated the accesiblity of this regime in a three-terminal Josephson jucntion using a split-gate quantum point contact like geomtery. These devices are built upon InAs two-dimensional electron gas proximitized by epitaxial aluminum providing high interface transperancy and gate tunablity.
Multi-terminal josephson devices can act as a network of two-terminal Josephson junctions when many conductance modes are present between different legs of the multi-terminal device [5,6]. Recently, we showed that these devices can show non-reciprocal supercurrent [7], a phenomena known as Josephson diode effect [8]. This effect can have potential applications in design of dissipationless electronics. Our work showed that this effect can be realized independent of the material system used, providing a robust and scalable way to make Josepshon diode devices.
[1] Riwar, R.P. et al., Nat. Commun. 7, 11167 (2016).
[2] Xie, H.Y. et al., Phys. Rev. B. 105, L241404 (2022).
[3] Eriksson, E. et al., Phys. Rev. B 95, 075417 (2017).
[4] Meyer, J.S. et al., Phys. Rev. Lett. 119, 136807 (2017).
[5] Graziano, G.V. et al., Nature Communications 13, 5933 (2022).
[6] Graziano, G.V. et al., Phys. Rev. B 101, 054510 (2020).
