Ultrasensitive magnetic field detection using a single artificial atom

TL;DR

This paper demonstrates an ultrahigh sensitivity magnetometer using a single superconducting artificial atom, achieving detection sensitivity comparable to traditional methods and highlighting the potential of quantum systems for magnetic sensing.

Contribution

The authors introduce a novel magnetometry technique employing a single superconducting two-level system, achieving unprecedented sensitivity in a micron-scale device.

Findings

Sensitivity of 2.7 pT/√Hz at 10 MHz achieved

Potential to improve sensitivity by over an order of magnitude

Comparable performance to DC-SQUIDs and atomic magnetometers

Abstract

Efficient detection of magnetic fields is central to many areas of research and has important practical applications ranging from materials science to geomagnetism. High sensitivity detectors are commonly built using direct current-superconducting quantum interference devices (DC-SQUIDs) or atomic systems. Here we use a single artificial atom to implement an ultrahigh sensitivity magnetometer with a size in the micron range. The artificial atom is a superconducting two-level system at low temperatures, operated in a way similar to atomic magnetometry. The high sensitivity results from quantum coherence combined with strong coupling to magnetic field. By employing projective measurements, we obtain a sensitivity of $2.7\, \t{pT}/\sqrt{\t{Hz}}$ at 10 MHz. We discuss feasible improvements that will increase the sensitivity by over one order of magnitude. The intrinsic sensitivity of this method to AC fields in the 100 kHz - 10 MHz range compares favourably with DC-SQUIDs and atomic magnetometers of equivalent spatial resolution. This result illustrates the potential of artificial quantum systems for sensitive detection and related applications.