Events on Tuesday, September 21st, 2021
- Correlated Charge Noise and Relaxation Errors in Superconducting Qubits
- Time: 2:00 pm
- Place: Zoom:
- Speaker: Chris Wilen, Physics PhD Graduate Student
- Abstract: A crucial requirement to the surface code is that errors cannot be correlated. Here, we characterize a superconducting multiqubit circuit and find that charge fluctuations are highly correlated on a length scale over 600~μm; moreover, discrete charge jumps are accompanied by a strong transient suppression of qubit energy relaxation time across the millimeter-scale chip. The resulting correlated errors are explained in terms of the charging event and phonon-mediated quasiparticle poisoning associated with absorption of gamma rays and cosmic-ray muons in the qubit substrate. Robust quantum error correction will require the development of mitigation strategies to protect multiqubit arrays from correlated errors due to particle impacts.
- Host: Robert McDermott, faculty advisor