Quantum-enhanced magnetometry by phase estimation algorithms with a single artificial atom

Danilin, S. , Lebedev, A.V., Vepsäläinen, A., Lesovik, G.B., Blatter, G. and Paraoanu, G.S. (2018) Quantum-enhanced magnetometry by phase estimation algorithms with a single artificial atom. npj Quantum Information, 4, 29. (doi: 10.1038/s41534-018-0078-y)

Abstract

Phase estimation algorithms are key protocols in quantum information processing. Besides applications in quantum computing, they can also be employed in metrology as they allow for fast extraction of information stored in the quantum state of a system. Here, we implement two suitably modified phase estimation procedures, the Kitaev and the semiclassical Fourier-transform algorithms, using an artificial atom realized with a superconducting transmon circuit. We demonstrate that both algorithms yield a flux sensitivity exceeding the classical shot-noise limit of the device, allowing one to approach the Heisenberg limit. Our experiment paves the way for the use of superconducting qubits as metrological devices which are potentially able to outperform the best existing flux sensors with a sensitivity enhanced by few orders of magnitude.

• Item Type: Articles
• Additional Information: The work was supported by the Government of the Russian Federation (Agreement 05.Y09.21.0018) (G. L.), by the RFBR Grant No. 17-02-00396A (G. L.), by the Foundation for the Advancement of Theoretical Physics “BASIS” (G. L.), by the Pauli Center for Theoretical Studies at ETH Zurich (G. L.) and by the Swiss National Foundation through the NCCR QSIT (A.L.) and the Ministry of Education and Science of the Russian Federation 16.7162.2017/8.9 (A.L.). We acknowledge financial support from Väisalä Foundation, the Academy of Finland (project 263457, Centers of Excellence “Low Temperature Quantum Phenomena and Devices”—project 250280 and “Quantum Technologies Finland”—project 312296), and the Centre for Quantum Engineering at Aalto University.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Danilin, Dr Sergey
• Authors: Danilin, S., Lebedev, A.V., Vepsäläinen, A., Lesovik, G.B., Blatter, G., and Paraoanu, G.S.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: npj Quantum Information
• Publisher: Nature Research
• ISSN: 2056-6387
• ISSN (Online): 2056-6387
• Copyright Holders: Copyright © 2018 The Authors
• First Published: First published in npj Quantum Information 4: 29
• Publisher Policy: Reproduced under a Creative Commons License