Abstract

I will discuss superconducting qubits and quantum dot spin qubits. The basic physics of these platforms is fairly understood and non-controversial. The bigger circuits tend to use similar materials, such as aluminum and silicon. These are a great superconductor and a great semiconductor, for device applications. But similar qubits can also be made out of different materials which come with larger gaps, stronger spin-orbit interaction, electrical and not magnetic tunability and other nominal advantages. We are working on unexplored materials for those, namely Sn-based InAs nanowire Josephson junctions and PbTe nanowire quantum dots. Of course new materials are less mature as device platforms, but trying to make them perform can offer valuable lessons and expand our understanding of what works and why. Mainstream technologies can hit future bottlenecks and having reserve ideas will come in handy. For instance, our InAs-Sn transmonos have reached a T1 relaxation time of 27 microseconds, only one order of magnitude below state-of-the-art. How far can we go?