Congrats to Christian Jünger and Andreas Baumgarter: the paper entitled Intermediate states in Andreev bound state fusion is finally out in Comm. Physics. The paper makes use of the best quantum dots (QDs) known to us. These QDs are grown by a team led by Prof. Kimberly A. Dick at Lund University in InAs nanowires making use of crystal-face control. We added superconducting contacts to both sides of a single QD in a nanowire. Due to the good transparency of the contacts, Andreev bound states (ABSs) form between the contacts and the lead sections that connect the two contact to the QD on both sides. While increasing the carrier concentration in the leads, we continously monitor how the two ABSs fuse together into a single “molecular ABS” that can carry a supercurrent.

Schematics of the evolution of two uncoupled Andreev-bound states resting in the two lead segements and the superconducting contacts S1, S2 into a fused molecular Andreev state

 

Andreev Bound State Fusion