Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Bulletin of the American Physical Society

A phase qubit coupled to an RF-SQUID resonator

Jed D. Whittaker, Shane Allman, Katarina Cicak, François Nguyen, Adam J. Sirois, John D. Teufel, Eva Zakka-Bajjani, Raymond W. Simmonds

Published Mar 21, 2011• 0 citations
OpenAlex

Related papers

Coupling a SQUID array resonator with a semiconductor charge qubit

Anna Stockklauser, Pasquale Scarlino, Jonne Koski +7 more

Bulletin of the American Physical Society•Mar 16, 2017•0 citations

Implementation of Qubits by Coaxial RF Squids

Bernard Rosen

APS•Apr 1, 1997•0 citations

Progress towards a metastable RF squid (MRFS) qubit

Archana Kamal, Andrew J. Kerman, Simon Gustavsson +8 more

Bulletin of the American Physical Society•Mar 4, 2014•0 citations

A tunable rf SQUID manipulated as flux and phase qubits

Stefano Poletto, CHIARELLO F., CASTELLANO M. G. +4 more

•Jan 1, 2009•0 citations

Tunable Resonant and Nonresonant Interactions between a Phase Qubit and L C Resonator

Michael S. Allman, Jed D. Whittaker, Manuel A. Castellanos-Beltran +8 more

We use a flux-biased radio frequency superconducting quantum interference device (rf SQUID) with an embedded flux-biased direct current SQUID to generate strong resonant and nonresonant tunable interactions between a phase qubit and a lumped-element resonator. The rf SQUID creates a tunable magnetic susceptibility between the qubit and resonator providing resonant coupling strengths from zero to near the ultrastrong coupling regime. By modulating the magnetic susceptibility, nonresonant parametric coupling achieves rates >100 MHz. Nonlinearity of the magnetic susceptibility also leads to parametric coupling at the subharmonics of the qubit-resonator detuning.

Physical Review Letters•Mar 26, 2014•74 citations

Parasitic RF-SQUIDs in superconducting qubits due to wirebonds

Benedikt Berlitz, Etienne Daum, Steffen Deck +2 more

Abstract Superconducting qubits show great promise to realize practical quantum computers from micro-fabricated integrated circuits. However, their solid-state architecture bears the burden of parasitic modes in qubit materials and the control circuitry which cause decoherence and interfere with qubits. Here, we present evidence that wirebonds, which are used to contact the micro-circuits and to realize chip-to-chip airbridges, may contain parasitic Josephson junctions. In our experiment, such a junction was enclosed in a superconducting loop and so gave rise to the formation an RF-SQUID which interfered with a nearby flux-tunable transmon qubit. Periodic signatures observed in magnetic field sweeps revealed a strong AC-dispersive coupling of the parasitic RF-SQUID to both the qubit and its readout resonator, in addition to the DC-inductive coupling between RF-SQUID and qubit. Our finding sheds light on a previously unknown origin of decoherence due to parasitic Josephson junctions in superconducting circuits.

arXiv:2505.20458•Superconductor Science and Technology•Aug 20, 2025•0 citations
We use a flux-biased radio frequency superconducting quantum interference device (rf SQUID) with an embedded flux-biased direct current SQUID to generate strong resonant and nonresonant tunable interactions between a phase qubit and a lumped-element resonator. The rf SQUID creates a tunable magnetic susceptibility between the qubit and resonator providing resonant coupling strengths from zero to near the ultrastrong coupling regime. By modulating the magnetic susceptibility, nonresonant parametric coupling achieves rates >100 MHz. Nonlinearity of the magnetic susceptibility also leads to parametric coupling at the subharmonics of the qubit-resonator detuning.
Abstract Superconducting qubits show great promise to realize practical quantum computers from micro-fabricated integrated circuits. However, their solid-state architecture bears the burden of parasitic modes in qubit materials and the control circuitry which cause decoherence and interfere with qubits. Here, we present evidence that wirebonds, which are used to contact the micro-circuits and to realize chip-to-chip airbridges, may contain parasitic Josephson junctions. In our experiment, such a junction was enclosed in a superconducting loop and so gave rise to the formation an RF-SQUID which interfered with a nearby flux-tunable transmon qubit. Periodic signatures observed in magnetic field sweeps revealed a strong AC-dispersive coupling of the parasitic RF-SQUID to both the qubit and its readout resonator, in addition to the DC-inductive coupling between RF-SQUID and qubit. Our finding sheds light on a previously unknown origin of decoherence due to parasitic Josephson junctions in superconducting circuits.