Superconducting qubits

I am mostly interested in the dynamics of quantum phase slips and quasiparticles, which affect the qubit performance, and collaborate closely with the experimentalists led at Yale by Rob Schoelkopf and Michel Devoret.

Building on our earlier theory work, http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.89.096802, a new type of a qubit – fluxonium – was developed, http://arxiv.org/abs/0906.0831. It allowed the detection – I believe, for the first time – of the interference between quantum phase slips in long 1D arrays of Josephson junctions, http://arxiv.org/abs/1012.1928.

We also constructed a comprehensive theory of the quasiparticles effect on the qubit coherence times in: http://arxiv.org/abs/1101.1341 and http://arxiv.org/abs/1106.0829. That theory come to active use with the invention of the 3D cavity qubits, http://arxiv.org/abs/1105.4652, and eventually allowed us to resolve a long-standing “cosine-phi” puzzle in the dissipative part of Josephson current, http://www.nature.com/nature/journal/v508/n7496/full/nature13017.html.