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Observation of a controllable PI-junction in a 3-terminal Josephson device

Jian Huang·F. Pierre·Tero T. Heikkila·Frank K. Wilhelm·Norman O. Birge
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Abstract

Recently Baselmans et al. [Nature, 397, 43 (1999)] showed that the direction of the supercurrent in a superconductor/normal/superconductor Josephson junction can be reversed by applying, perpendicularly to the supercurrent, a sufficiently large control current between two normal reservoirs. The novel behavior of their 4-terminal device (called a controllable PI-junction) arises from the nonequilibrium electron energy distribution established in the normal wire between the two superconductors. We have observed a similar supercurrent reversal in a 3-terminal device, where the control current passes from a single normal reservoir into the two superconductors. We show theoretically that this behavior, although intuitively less obvious, arises from the same nonequilibrium physics present in the 4-terminal device. Moreover, we argue that the amplitude of the PI-state critical current should be at least as large in the 3-terminal device as in a comparable 4-terminal device.

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Jian Huang, F. Pierre, Tero T. Heikkila, Frank K. Wilhelm, Norman O. Birge. 2002-06-03. Observation of a controllable PI-junction in a 3-terminal Josephson device. https://doi.org/10.1103/physrevb.66.020507

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