H
Helen S. Margolis
Researcher at National Physical Laboratory
Publications - 127
Citations - 3766
Helen S. Margolis is an academic researcher from National Physical Laboratory. The author has contributed to research in topics: Atomic clock & Laser. The author has an hindex of 30, co-authored 124 publications receiving 3233 citations. Previous affiliations of Helen S. Margolis include University of Oxford.
Papers
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Journal ArticleDOI
Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants.
R. M. Godun,P. B. R. Nisbet-Jones,J. M. Jones,S. A. King,L. A. M. Johnson,Helen S. Margolis,Krzysztof Szymaniec,S. N. Lea,Kai Bongs,Patrick Gill +9 more
TL;DR: This work presents the first direct measurement of the frequency ratio of these two clock transitions, without reference to a cesium primary standard, and using the same single ion of 171Yb+.
Journal ArticleDOI
Geodesy and metrology with a transportable optical clock
Jacopo Grotti,Silvio Koller,Stefan Vogt,Sebastian Häfner,Uwe Sterr,Christian Lisdat,Heiner Denker,Christian Voigt,Ludger Timmen,Antoine Rolland,Fred N. Baynes,Helen S. Margolis,Michel Zampaolo,Pierre Thoumany,Marco Pizzocaro,Benjamin Rauf,Filippo Bregolin,Anna Tampellini,Piero Barbieri,Massimo Zucco,Giovanni Antonio Costanzo,Cecilia Clivati,Filippo Levi,Davide Calonico +23 more
TL;DR: The first field measurement campaign with a transportable optical lattice clock was reported in this article, where the authors used it to determine the gravity potential difference between the middle of a mountain and a location 90 km away.
Journal ArticleDOI
Hertz-level measurement of the optical clock frequency in a single 88Sr+ ion.
Helen S. Margolis,Geoffrey P. Barwood,Guilong Huang,H. A. Klein,S. N. Lea,Krzysztof Szymaniec,Patrick Gill +6 more
TL;DR: Improvements required to obtain a cesium-limited frequency measurement are described and are expected to lead to a 88Sr+ optical clock with stability and reproducibility exceeding that of the primary cedium standard.
Journal ArticleDOI
The CODATA 2017 values of h, e, k, and N A for the revision of the SI
David B. Newell,F Cabiati,J Fischer,K Fujii,Savely G. Karshenboim,Helen S. Margolis,E. de Mirandes,Peter J. Mohr,F. Nez,Krzysztof Pachucki,Terry Quinn,Barry N. Taylor,M Wang,B M Wood,Z Zhang +14 more
TL;DR: In this paper, the exact values of the Planck constant h, elementary charge e, Boltzmann constant k, and Avogadro constant N A from the CODATA 2017 Special Adjustment of the Fundamental Constants are presented.
Journal ArticleDOI
Test of Special Relativity Using a Fiber Network of Optical Clocks.
P. Delva,Jérôme Lodewyck,S. Bilicki,E. Bookjans,Gregoire Vallet,R. Le Targat,Paul-Eric Pottie,C. Guerlin,F. Meynadier,C. Le Poncin-Lafitte,Olivier Lopez,Anne Amy-Klein,Won-Kyu Lee,Nicolas Quintin,Christian Lisdat,A. Al-Masoudi,S. Dörscher,Christian Grebing,Gesine Grosche,A. Kuhl,S. M. F. Raupach,Uwe Sterr,Ian R. Hill,Richard Hobson,William B. Bowden,J. Kronjäger,Giuseppe Marra,Antoine Rolland,Fred N. Baynes,Helen S. Margolis,Patrick Gill +30 more
TL;DR: This work obtains a constraint on the Robertson-Mansouri-Sexl parameter |α|≲1.1×10^{-8}, quantifying a violation of time dilation, thus improving by a factor of around 2 the best known constraint obtained with Ives-Stilwell type experiments.