Anuj Aggarwal, Quantum Technology

Abstract:  

Flux-tunable qubits and couplers have become crucial components in superconducting quantum
processors. However, dynamically controlling their frequency via flux pulses poses challenges due
to distortions and transients in the flux control signal. In particular, long-time transients can persist, adversely affecting subsequent qubit control operations and degrading overall processor performances.
In this seminar, we show that the flux control line can be modelled as a first-order RC circuit, and we introduce a novel class of flux pulses designed to mitigate these transients. We experimentally
demonstrate the suppression of transients using an example pulse on a flux-tunable coupler.
The proposed pulse design offers a practical solution for mitigating long-time transients, enabling
efficient and reliable experiment tune-ups without requiring detailed flux line characterization.

Discussion leader: Simone Gasparinetti, Professor, QT

Main supervisor: Giovanna Tancredi Sammarco, Senior researcher

Assistant supervisor: Jonas Bylander, Professor

Examiner: Per Delsing, Professor