Constraints on Stable Equilibria with Fluctuation-Induced (Casimir) Forces
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
- Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Koeln (Germany)
We examine whether fluctuation-induced forces can lead to stable levitation. First, we analyze a collection of classical objects at finite temperature that contain fixed and mobile charges and show that any arrangement in space is unstable to small perturbations in position. This extends Earnshaw's theorem for electrostatics by including thermal fluctuations of internal charges. Quantum fluctuations of the electromagnetic field are responsible for Casimir or van der Waals interactions. Neglecting permeabilities, we find that any equilibrium position of items subject to such forces is also unstable if the permittivities of all objects are higher or lower than that of the enveloping medium, the former being the generic case for ordinary materials in vacuum.
- OSTI ID:
- 21470945
- Journal Information:
- Physical Review Letters, Vol. 105, Issue 7; Other Information: DOI: 10.1103/PhysRevLett.105.070404; (c) 2010 American Institute of Physics; ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CASIMIR EFFECT
DISTURBANCES
ELECTROMAGNETIC FIELDS
ELECTROSTATICS
EQUILIBRIUM
FLUCTUATIONS
LEVITATION
PERMITTIVITY
QUANTUM ELECTRODYNAMICS
VAN DER WAALS FORCES
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
ELECTRODYNAMICS
FIELD THEORIES
PHYSICAL PROPERTIES
QUANTUM FIELD THEORY
VARIATIONS