Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 52: Superconducting Electronics: SQUIDs, Qubits, Circuit QED, Quantum Coherence and Quantum Information Systems 2 (joint session TT/HL)

TT 52.3: Vortrag

Donnerstag, 19. März 2020, 10:00–10:15, HSZ 03

High power dispersive qubit readout and state preparation without parametric amplifier — •Martin Spiecker1, Daria Gusenkova1, Richard Gebauer2, Lukas Grünhaupt1, Patrick Winkel1, Francesco Valenti1,2, Ivan Takmakov1,2,3, Dennis Rieger1, Alexey V. Ustinov1,4, Wolfgang Wernsdorfer1,3,5, Oliver Sander2, and Ioan M. Pop1, 31Physikalisches Institut, KIT, Germany — 2Institute for Data Processing and Electronics, KIT, Germany — 3Institute of Nanotechnology, KIT, Germany — 4Russian Quantum Center, MISIS, Moscow, Russia — 5Institute Neel, CNRS, Grenoble, France

High-fidelity qubit readout is an essential requirement for fault-tolerant quantum algorithms. In theory, within the dispersive readout scheme, the state discrimination can be improved significantly if the resonator’s photon population increases [1]. However, in practice the optimal photon number does usually not exceed 2.5 photons [2], and parametric amplifiers are needed to achieve a substantial signal-to-noise ratio.
In order to investigate the limitations of the readout fidelity we used a fluxonium qubit with a granular aluminum superinductance [3] having the advantage of reduced nonlinearity in comparison to previously used Josephson junction arrays. We demonstrate qubit measurements without a parametric amplifier at readout powers corresponding up to 200 photons in the resonator.

[1] A. Blais et al., PRA 69(6), 062320 (2004)

[2] T. Walter et al., PRA 7.5, 054020 (2017)

[3] L. Grünhaupt and M. Spiecker et al., Nat. Mater. 18, 816-819 (2019)

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2020 > Dresden