Abstract: 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 full toolkit, which is required for many proposed applications of multi-terminal Josephson junctions (MTJJs), is not available on any other material platform. In this talk, I 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 and non-linear intermodulation of signals in ambient magnetic fields, with full electrostatic control [4]. I will discuss how our recent developments establish a viable path for creating topological Josephson matter [5] at the device level.
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, arXiv:2312.17703 (2023).
[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).
