1/f Flux Noise in Josephson Phase Qubits

Abstract

We present a new method to measure 1/f noise in Josephson quantum bits (qubits) that yields low-frequency spectra below 1Hz. Comparison of noise taken at positive and negative bias of a phase qubit shows the dominant noise source to be flux noise and not junction critical-current noise, with a magnitude similar to that measured previously in other systems. Theoretical calculations show that the level of flux noise is not compatible with the standard model of noise from two-level state defects in the surface oxides of the films.

4 pages, 3 figures

References in corpus (5)

• Resolving photon number states in a superconducting circuit
• Decoherence of flux qubits due to 1/f flux noise
• State tomography of capacitively shunted phase qubits with high fidelity
• Model for l/f Flux Noise in SQUIDs and Qubits
• Low- and high-frequency noise from coherent two-level systems

Cited by in corpus (19)

• How to Enhance Dephasing Time in Superconducting Qubits
• Magnetism in SQUIDs at Millikelvin Temperatures
• Decoherence in qubits due to low-frequency noise
• Microscopic origin of low frequency flux noise in Josephson circuits
• Measurement-induced qubit state mixing in circuit QED from up-converted dephasing noise
• Decoherence of superconducting qubits caused by quasiparticle tunneling
• Probing Noise in Flux Qubits via Macroscopic Resonant Tunneling
• Geometrical dependence of low frequency noise in superconducting flux qubits
• Spin-like susceptibility of metallic and insulating thin films at low temperature
• Macroscopic Resonant Tunneling in the Presence of Low Frequency Noise
• Correlated flux noise and decoherence in two inductively coupled flux qubits
• Noise Spectroscopy Using Correlations of Single-Shot Qubit Readout
• Probing High Frequency Noise with Macroscopic Resonant Tunneling
• Efficient one- and two-qubit pulsed gates for an oscillator stabilized Josephson qubit
• Spin-echo entanglement protection from random telegraph noise
• Quantum instability in a dc-SQUID with strongly asymmetric dynamical parameters
• Generating strong magnetic flux shielding regions in a single crystal of Bi2Sr2CaCu2O8 using a blind hole array
• Coupling mechanism between microscopic two-level system and superconducting qubits
• Effect of Ohmic environment on optimally controlled flux-biased phase qubit