Liberating Quantum Processors from Parasitic Interactions*

I explain two methods for zeroing parasitic interaction between a pair of qubits. A year ago, for the first time we showed that magnetic modulation helps to set the interaction to zero in a hybrid circuit containing a transmon coupled to a flux qubits. Most recently we developed the theory and showed the possibility of zeroing parasitic interaction in non-modulable fixed parameter qubits. For this we need to use microwave driving, and we named this technique "dynamic cancellation."  This owes to a fundamental symmetry in the Hamiltonian of superconducting processors. Using our understanding of parasitic interactions and how to eliminate them, one can aim for perfect two qubit gate. One example I show is PF gate.