Measurement disturbance tradeoffs in three-qubit unsupervised quantum classification

Spencer-Wood, H., Jeffers, J. and Croke, S. (2022) Measurement disturbance tradeoffs in three-qubit unsupervised quantum classification. Physical Review A: Atomic, Molecular and Optical Physics, 105(6), 062447. (doi: 10.1103/PhysRevA.105.062447)

Abstract

We consider measurement disturbance tradeoffs in quantum machine learning protocols which seek to learn about quantum data. We study the simplest example of a binary classification task in the unsupervised regime. Specifically, we investigate how a classification of two qubits, that can each be in one of two unknown states, affects our ability to perform a subsequent classification on three qubits when a third is added. Surprisingly, we find a range of strategies in which a nontrivial first classification does not affect the success rate of the second classification. There is, however, a nontrivial measurement disturbance tradeoff between the success rate of the first and second classifications, and we fully characterize this tradeoff analytically.

• Item Type: Articles
• Additional Information: The authors acknowledge The Engineering and Physical Sciences Research Council and the UK National Quantum Technologies Programme via the QuantIC Quantum Imaging Hub (EP/T00097X/1). Sarah Croke is supported by a Leverhulme Fellowship (RF-2020-397).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Spencer-Wood, Mr Hector and Croke, Dr Sarah
• Authors: Spencer-Wood, H., Jeffers, J., and Croke, S.
• College/School: College of Science and Engineering > School of Mathematics and Statistics; College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review A: Atomic, Molecular and Optical Physics
• Publisher: American Physical Society
• ISSN: 2469-9926
• ISSN (Online): 2469-9934
• Published Online: 27 June 2022
• Copyright Holders: Copyright © 2022 American Physical Society
• First Published: First published in Physical Review A: Atomic, Molecular and Optical Physics 105(6): 062447
• Publisher Policy: Reproduced in accordance with the publisher copyright policy

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
305567		QuantIC - The UK Quantum Technoogy Hub in Quantum Enhanced Imaging	Miles Padgett	Engineering and Physical Sciences Research Council (EPSRC)	EP/T00097X/1	P&S - Physics & Astronomy
309544		Exploring Wigner's theorem: Observable quantities and symmetry transformations from the perspective of quantum reference frames.	Sarah Croke	Leverhulme Trust (LEVERHUL)	RF-2020-397\9	P&S - Physics & Astronomy