Multi-terminal Josephson junctions: A road to topological flux networks

Abstract

Multi-terminal Josephson junctions were recently proposed as a versatile and tunable platform to emulate topological Bloch-like Hamiltonians in arbitrary dimensions. In this perspective article, we will give a brief overview of the subject and recognize these mesoscopic devices as realizations of topological flux networks as the ones envisioned by J. E. Avron and coworkers in their seminal works on the early days of the quantum Hall effect. We summarize the current state-of-the-art theoretical and experimental research regarding these Josephson devices, highlighting recent developments and giving an outlook on current trends.

Quantum interferometer for quartets in superconducting three-terminal Josephson junctions

“…Multiterminal Josephson junctions (MTJs) [1][2][3][4] appear as a very fertile evolution in the field of superconductivity. While unbiased MTJs offer prospects as platforms for controllable topological properties [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], biased MTJs reveal new channels for both superconducting phase-sensitive and quantum mechanical DC currents, as predicted by theory [22,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] and confirmed in experiments [43][44][45][46][47]…”

Ground state topology of a four-terminal superconducting double quantum dot

“…Prime examples are topological photonics [9,10], topological driven Floquet systems [11] and topological electrical circuits [12]. This idea was also successfully transferred to multiterminal Josephson junctions that can host topological Andreev bound states in the space of superconducting phase differences [13][14][15][16][17][18][19][20][21][22][23][24][25][26] or topological superconducting circuits. [27][28][29].…”