Frequency precision in fixed-frequency transmon qubits, and implications for scalable fault-tolerant quantum computing circuits.

Lattices of fixed-frequency transmon qubits coupled via cross-resonance gates are a promising platform for practical fault-tolerant quantum computing circuits. A key challenge in scaling up this design is to set the qubit frequencies so as to optimize the cross-resonance gates and avoid 'frequency collisions'. In this talk we will discuss such behavior in light of the statistical variations in qubit frequency that derive from process variability in qubit fabrication.