Topic: Superconducting qubits

Seminar by Morten Kjaergaard (Niels Bohr Institute, University of Copenhagen) on rapid FPGA-based feedback for superconducting qubits, including sparse-sampling techniques and on-FPGA inference enabling millisecond-timescale T1 estimation, ~100 ms readout optimization, and over 74,000 consecutive recalibrations in closed-loop operation.

John Clarke, Michel H. Devoret and John M. Martinis trace the discovery that a macroscopic electrical circuit can display quantum tunnelling and discrete energy levels. Clarke connects early superconducting measuring devices with experiments on current-biased Josephson junctions. Microwave-induced resonances and the crossover from thermal activation to temperature-independent escape provide tests of quantum behaviour. Devoret explains how superconducting circuits became controllable artificial atoms, with Josephson elements enabling engineered energy spectra, qubits and quantum-limited amplif