Superconductor-semiconductor multi-terminal Josephson junctions

Josephson junctions between more than two superconductors have recently come to the fore as an extension of the traditional Josephson paradigm that provides new opportunities for science and potential technologies. Combining the multi-terminal concept with hybrid superconducting-semiconducting materials is particularly promising as it enables phenomena based on the interplay between superconductivity, quantum confinement, ballistic transport and gate-tuning of superconducting couplings [1,2]. This talk will describe recent evidence from our group on achieving quantum correlations between Cooper pairs across the terminals of MTJJs [3], as well as the ability of MTJJs to host non-reciprocal superconductivity (superconducting diode effect) and non-linear intermodulation of signals in ambient magnetic fields, with full electrostatic control [4]. The talk will also connect these recent developments with ongoing efforts to create topological Josephson matter [5] using Abdreev bound states in MTJJs.



References:

[1] G. Graziano et al., Transport studies in a gate-tunable three-terminal Josephson junction, Phys. Rev. B 101, 054510 (2020).

[2] G. Graziano, M. Gupta et al., Selective control of conductance modes in multi-terminal Josephson junctions, Nature Communications 13, 5933 (2022).

[3] M. Gupta et al., Evidence for π-shifted Cooper quartets in PbTe nanowire three-terminal Josephson junctions, Nano Letters 24, 13903 (2024).

[4] M. Gupta et al., Gate-tunable superconducting diode effect in a three-terminal Josephson device, Nature Communications 14, 3078 (2023).

[5] R. Riwar et al., Multi-terminal Josephson junctions as topological matter, Nature Communications 7, 11167 (2016).