A cold stream of electron pairs with no resistance, a wild rush across the highway.
A Josephson Junction is a tiny but powerful device governed by the laws of quantum mechanics. It is composed of one layer of non-superconducting material sandwiched between two layers of superconducting material. Normally, electrons cannot pass through non-conductive material. However, when it is cooled down to very low temperatures, pairs of electrons can tunnel through the non-superconducting barrier.
This device has two distinct states: below a critical current, the voltage across the junction remains at zero, while above the threshold, an oscillating voltage emerges. This versatile device can be transformed into an artificial atom, representing a formidable contender to photonic and trapped ion quantum computers.
You've certainly been close to Josephson Junctions before.