title: Ultrasensitive magnetic field detection using a single artificial atom.
abstract: Efficient detection of magnetic fields is central to many areas of research and technology. High-sensitivity detectors are commonly built using direct-current superconducting quantum interference devices or atomic systems. Here we use a single artificial atom to implement an ultrasensitive magnetometer with micron range size. The artificial atom, a superconducting two-level system, is operated similarly to atom and diamond nitrogen-vacancy centre-based magnetometers. The high sensitivity results from quantum coherence combined with strong coupling to magnetic field. We obtain a sensitivity of 3.3 pT Hz(-1/2) for a frequency at 10 MHz. We discuss feasible improvements to increase sensitivity by one order of magnitude. The intrinsic sensitivity of this detector at frequencies in the 100 kHz-10 MHz range compares favourably with direct-current superconducting quantum interference devices and atomic magnetometers of equivalent spatial resolution. This result illustrates the potential of artificial quantum systems for sensitive detection and related applications.
authors.affiliation: Institute for Quantum Computing, Department of Physics and Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
authors.forename: M
authors.initials: M
authors.lastname: Bal
authors.forename: C
authors.initials: C
authors.lastname: Deng
authors.forename: J-L
authors.initials: JL
authors.lastname: Orgiazzi
authors.forename: F R
authors.initials: FR
authors.lastname: Ong
authors.forename: A
authors.initials: A
authors.lastname: Lupascu