CoQuS-Talk by Eugene S. Polzik; Niels Bohr Institute, University of Copenhagen

23.04.2018 17:30 - 17:30

"Tracking motion beyond the uncertainty limits"

Quantum mechanics dictates that a continuous measurement of the position of an object imposes a random quantum back action (QBA) perturbation on its momentum. This randomness translates with time into position uncertainty, thus leading to the well known uncertainty on the measurement of motion. As a consequence, and in accordance with the Heisenberg uncertainty principle, the QBA puts a limitation—the so-called standard quantum limit—on the precision of sensing of position, velocity and acceleration. In this talk I will present the ideas [1] and experimental results [2] for measurement of motion of a mechanical oscillator with the precision not restricted by the QBA. This is achieved by measuring the motion in a special reference frame linked to an atomic spin system with an effective negative mass. Applications to force sensing [3], clock synchronization [4] and gravitational wave detection [5] will be discussed.

[1] E.S. Polzik and K.Hammerer.  Annalen der Physik. 527, No. 1–2, A15–A20 (2015). K. Hammerer et al,  PRL. 102, 020501 (2009).[2] C. Møller et al. Nature, 547, 191 (2017).[3] X. Huang, et al. arXiv:1801.02569.[4] E. S. Polzik and J. Ye. PRA, 93, 021404 (2016).[5] F. Khalili and E. S. Polzik, arXiv:1710.10405


Monday 23 April,2018

16:30h get-together with coffee and snacks!


Hlawka Hörsaal (HS 9), Gußhausstraße 27-29, 1040 Vienna


The seminar talk will be preceded by a CoQuS Student talk at 17:00h by

Moritz Wenclawiak

TU Wien

"Strong coupling experiments in the THz regime"

Hosted by: Arno Rauschenbeutel



Hlawka Hörsaal (HS 9), Gußhausstraße 27-29, 1040 Vienna