Parametric controls and modular quantum computing in superconducting quantum circuits
Parametric driving has long been used in weakly nonlinear superconducting circuits to create nearly quantum-limited ‘parametric’ amplifiers, which are in wide use for the readout of superconducting qubits. However, the off-resonant terms we can activate with parametric driving are ubiquitous in Josephson-junction based circuits. In this talk, I’ll review the basics of how we identify and engineer parametric controls in the laboratory and use them in a variety of applications including qubit bath engineering, and single- and multi-qubit gates. I will focus on how we are using parametric controls based on the third order nonlinearity of SNAILs to create all-to-all couplings among transmon qubits in small quantum modules, as well as construct quantum state routers to link these modules into large-scale quantum machines.