Fig. 5: Magnetic field dependence of coherence times for device A.
From: Industry-compatible silicon spin-qubit unit cells exceeding 99% fidelity
a–c, Spin lifetime T1 (a), Ramsey \({T}_{2}^{* }\) (b) and Hahn echo \({T}_{2}^{{\rm{Hahn}}}\) (c) metrics as functions of the applied magnetic field amplitude B0. We measured both qubits for each experiment interleaved and repeated this 50 (T1), 10,000 (\({T}_{2}^{* }\)) and 2,000 (\({T}_{2}^{{\rm{Hahn}}}\)) times. Ramsey experiments at B0 = 0.05 T, 0.1 T, 0.8 T and 1.1 T were repeated 50,000, 100,000, 50,000 and 40,000 times. The Hahn echo experiment at B0 = 1.3 T was repeated 500 times. Between each repeat we used real-time Larmor frequency feedback following the protocol described in ref. 39. The data were fitted using the functions described in Extended Data Fig. 2. Data shown as stars correspond to metrics measured during two-qubit benchmarking (Extended Data Fig. 2), using a method and gate voltages that differed from those used for the magnetic field sweep. Error bars represent the 95% confidence level.
