Left: A quantum processor similar to the one that was used to investigate qubit performance fluctuations. One qubit is highlighted in blue. Right: One qubit’s energy-relaxation time “T1” plotted as a function of it’s operating frequency and time. We see energy-relaxation hotspots, which our data suggest are due to material defects (black arrowheads). The motion of these hotspots into and out-of resonance with the qubit are responsible for the most significant energy-relaxation fluctuations. Note that these data were taken over a frequency band with an above-average density of defects. |