Sharp transitions in low-number quantum dots Bayesian magnetometry

Paweł Mazurek; Michał Horodecki; Łukasz Czekaj; Paweł Horodecki

doi:10.1038/srep34327

Sharp transitions in low-number quantum dots Bayesian magnetometry

Sci Rep. 2016 Sep 30:6:34327. doi: 10.1038/srep34327.

Authors

Paweł Mazurek^{1

2}, Michał Horodecki^{1

2}, Łukasz Czekaj^{1

2}, Paweł Horodecki^{2

3}

Affiliations

¹ Institute of Theoretical Physics and Astrophysics, National Quantum Information Centre, Faculty of Mathematics, Physics and Informatics, University of Gdańsk, Wita Stwosza 57, 80-308 Gdańsk, Poland.
² National Quantum Information Centre in Gdańsk, Andersa 27, 81-824 Sopot, Poland.
³ Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.

Abstract

We consider Bayesian estimate of static magnetic field, characterized by a prior Gaussian probability distribution, in systems of a few electron quantum dot spins interacting with infinite temperature spin environment via hyperfine interaction. Sudden transitions among optimal states and measurements are observed. Usefulness of measuring occupation levels is shown for all times of the evolution, together with the role of entanglement in the optimal scenario. For low values of magnetic field, memory effects stemming from the interaction with environment provide limited metrological advantage.