Événements
Séminaire - François Swiadek
Date : 28 septembre 2023 14:00
Type : Institut Quantique
Lieu : Auditorium de l'IQ
ETH Zurich
Invité du Pr Alexandre Blais
Title: "Enhancing Dispersive Readout of SuperconductingQubits Through Dynamic Control of the Dispersive Shift: Experiment andTheory"
Abstract: "The performance of a wide range ofquantum computing algorithms and protocols depends critically on the fidelityand speed of the employed qubit readout. Examples include gate sequencesbenefiting from mid-circuit, real-time, measurement-based feedback, such asqubit initialization, entanglement generation, teleportation, and perhaps mostimportantly, quantum error correction. A prominent and widely-used readoutapproach is based on the dispersive interaction of a superconducting qubitstrongly coupled to a large-bandwidth readout resonator, frequently combinedwith a dedicated or shared Purcell filter protecting qubits from decay. Bydynamically reducing the qubit-resonator detuning and thus increasing thedispersive shift, we demonstrate a beyond-state-of-the-art two-state-readouterror of only 0.25% in 100 ns integration time. Maintaining low readout-drive strength,we nearly quadruple the signal-to-noise ratio of the readout by doubling thereadout mode linewidth, which we quantify by considering the hybridization ofthe readout-resonator and its dedicated Purcell-filter. We find excellentagreement between our experimental data and our theoretical model. Thepresented results are expected to further boost the performance of new andexisting algorithms and protocols critically depending on high-fidelity, fast,mid-circuit measurements."
Invité du Pr Alexandre Blais
Title: "Enhancing Dispersive Readout of SuperconductingQubits Through Dynamic Control of the Dispersive Shift: Experiment andTheory"
Abstract: "The performance of a wide range ofquantum computing algorithms and protocols depends critically on the fidelityand speed of the employed qubit readout. Examples include gate sequencesbenefiting from mid-circuit, real-time, measurement-based feedback, such asqubit initialization, entanglement generation, teleportation, and perhaps mostimportantly, quantum error correction. A prominent and widely-used readoutapproach is based on the dispersive interaction of a superconducting qubitstrongly coupled to a large-bandwidth readout resonator, frequently combinedwith a dedicated or shared Purcell filter protecting qubits from decay. Bydynamically reducing the qubit-resonator detuning and thus increasing thedispersive shift, we demonstrate a beyond-state-of-the-art two-state-readouterror of only 0.25% in 100 ns integration time. Maintaining low readout-drive strength,we nearly quadruple the signal-to-noise ratio of the readout by doubling thereadout mode linewidth, which we quantify by considering the hybridization ofthe readout-resonator and its dedicated Purcell-filter. We find excellentagreement between our experimental data and our theoretical model. Thepresented results are expected to further boost the performance of new andexisting algorithms and protocols critically depending on high-fidelity, fast,mid-circuit measurements."