Probing the Casimir force with optical tweezers
We propose to use optical tweezers to probe the Casimir interaction between microspheres inside a liquid medium for geometric aspect ratios far beyond the validity of the widely employed proximity force approximation. This setup has the potential for revealing unprecedented features associated to th...
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Published in | Europhysics letters Vol. 112; no. 4; pp. 44001 - p1-44001-p7 |
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Main Authors | , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Les Ulis
EDP Sciences, IOP Publishing and Società Italiana di Fisica
01.11.2015
IOP Publishing |
Subjects | |
Online Access | Get full text |
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Summary: | We propose to use optical tweezers to probe the Casimir interaction between microspheres inside a liquid medium for geometric aspect ratios far beyond the validity of the widely employed proximity force approximation. This setup has the potential for revealing unprecedented features associated to the non-trivial role of the spherical curvatures. For a proof of concept, we measure femtonewton double-layer forces between polystyrene microspheres at distances above 400 nm by employing very soft optical tweezers, with stiffness of the order of fractions of a fN/nm. As a future application, we propose to tune the Casimir interaction between a metallic and a polystyrene microsphere in saline solution from attraction to repulsion by varying the salt concentration. With those materials, the screened Casimir interaction may have a larger magnitude than the unscreened one. This line of investigation has the potential for bringing together different fields including classical and quantum optics, statistical physics and colloid science, while paving the way for novel quantitative applications of optical tweezers in cell and molecular biology. |
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Bibliography: | istex:D0AEB671BA9CE037D10BC17543DCCB06EB75C5FE publisher-ID:epl17517 ark:/67375/80W-Q6PJ83Q3-P ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0295-5075 1286-4854 |
DOI: | 10.1209/0295-5075/112/44001 |