Systematic Crosstalk Mitigation
for Superconducting Tunable Qubits

Invited seminar talk at AQT at LBNL, Oct 2020



Unwanted crosstalk between neighboring qubits is one of the dominant sources of noise in superconducting transmon architectures. To this end, we demonstrate how a software/architectural solution, when co-designed with hardware, accomplishes significant gain in performance and reliability. In particular, we present a general software solution to alleviate crosstalk by systematically tuning qubit frequencies according to input programs, trading parallelism for higher gate fidelity when necessary. The net result is that our work dramatically improves the crosstalk resilience of tunable-qubit, fixed-coupler hardware, matching or surpassing other more complex architectural designs such as tunable-coupler systems. Our methodology has a notable feature: it reduces a complex physical problem to a number of computer science subproblems, such as graph coloring and constraint satisfaction problem (CSP) techniques.