Resonant Readout of a Persistent Current Qubit
arXiv:cond-mat/0501283 · doi:10.1109/TASC.2005.850077
Abstract
We have implemented a resonant circuit that uses a SQUID as a flux-sensitive Josephson inductor for qubit readout. In contrast to the conventional switching current measurement that generates undesired quasi-particles when the SQUID switches to the voltage state, our approach keeps the readout SQUID biased along the supercurrent branch during the measurement. By incorporating the SQUID inductor in a high-Q resonant circuit, we can distinguish the two flux states of a niobium persistent-current (PC) qubit by observing a shift in the resonant frequency of both the magnitude and the phase spectra. The readout circuit was also characterized in the nonlinear regime to investigate its potential use as a nonlinear amplifier.
4 pages, 2004 ASC Proceedings
References in corpus (5)
- Coherent Quantum Dynamics of a Superconducting Flux Qubit
- An RF-Driven Josephson Bifurcation Amplifier for Quantum Measurements
- Continuous Monitoring of Rabi Oscillations in a Josephson Flux Qubit
- Nondestructive readout for a superconducting flux qubit
- Observation of macroscopic Landau-Zener transitions in a superconducting device
Cited by in corpus (7)
- RF bifurcation of a Josephson junction: microwave embedding circuit requirements
- Temperature Dependence of the Frequency and Noise of Superconducting Coplanar Waveguide Resonators
- Large-amplitude driving of a superconducting artificial atom: Interferometry, cooling, and amplitude spectroscopy
- Nonlinear resonant behavior of the dispersive readout scheme for a superconducting flux qubit
- Quantum nondemolition-like, fast measurement scheme for a superconducting qubit
- Phase-space theory for dispersive detectors of superconducting qubits
- Quantum teleportation between nanomechanical modes