DEMONSTRATING THE STRONG GEOMETRY DEPENDENCE OF THE CASIMIR FORCE ON A SURFACE WITH DEEP, NANOSCALE CORRUGATIONS

2010 ◽  
Vol 25 (11) ◽  
pp. 2212-2222 ◽  
Author(s):  
H. B. CHAN ◽  
Y. BAO ◽  
J. ZOU ◽  
R. A. CIRELLI ◽  
F. KLEMENS ◽  
...  
Keyword(s):  
Casimir Force ◽  
Flat Surface ◽  
Torsional Oscillator ◽  
Silicon Surfaces ◽  
Finite Conductivity ◽  
Additive Approximation ◽  
Corrugated Surfaces ◽  
Geometry Dependence ◽  
Proximity Force Approximation ◽  
Gold Sphere

We measure the Casimir force gradient between silicon surfaces with nanoscale, rectangular corrugations and a gold sphere attached to a micromechanical torsional oscillator. By comparing the force gradients on the corrugated surfaces to that on a smooth, flat surface of the same material, we demonstrate that the Casimir force deviates from the value expected from the pairwise additive approximation and the proximity force approximation. The observed deviation qualitatively agrees with calculations that take into account the interplay between finite conductivity and geometry effects. However, the agreement is not exact, possibly due to uncertainties in the optical properties of the silicon substrate.

scholarly journals THE SCATTERING APPROACH TO THE CASIMIR FORCE

2010 ◽  
Vol 25 (11) ◽  
pp. 2201-2211 ◽  
Author(s):  
S. REYNAUD ◽  
A. CANAGUIER-DURAND ◽  
R. MESSINA ◽  
A. LAMBRECHT ◽  
P. A. MAIA NETO
Keyword(s):  
Casimir Force ◽  
Nanostructured Surfaces ◽  
3D Space ◽  
Geometry Dependence ◽  
Specific Calculations ◽  
Proximity Force Approximation

We present the scattering approach which is nowadays the best tool for describing the Casimir force in realistic experimental configurations. After reminders on the simple geometries of 1d space and specular scatterers in 3d space, we discuss the case of stationary arbitrarily shaped mirrors in electromagnetic vacuum. We then review specific calculations based on the scattering approach, dealing for example with the forces or torques between nanostructured surfaces and with the force between a plane and a sphere. In these various cases, we account for the material dependence of the forces, and show that the geometry dependence goes beyond the trivial Proximity Force Approximation often used for discussing experiments.

scholarly journals Strong geometry dependence of the Casimir force between interpenetrated rectangular gratings

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mingkang Wang ◽  
L. Tang ◽  
C. Y. Ng ◽  
Riccardo Messina ◽  
Brahim Guizal ◽  
...  
Keyword(s):  
Casimir Force ◽  
Quantum Fluctuations ◽  
Complex Geometries ◽  
Casimir Forces ◽  
Recent Advances ◽  
Geometry Dependence ◽  
Proximity Force Approximation ◽  
On Chip

AbstractQuantum fluctuations give rise to Casimir forces between two parallel conducting plates, the magnitude of which increases monotonically as the separation decreases. By introducing nanoscale gratings to the surfaces, recent advances have opened opportunities for controlling the Casimir force in complex geometries. Here, we measure the Casimir force between two rectangular silicon gratings. Using an on-chip detection platform, we achieve accurate alignment between the two gratings so that they interpenetrate as the separation is reduced. Just before interpenetration occurs, the measured Casimir force is found to have a geometry dependence that is much stronger than previous experiments, with deviations from the proximity force approximation reaching a factor of ~500. After the gratings interpenetrate each other, the Casimir force becomes non-zero and independent of displacement. This work shows that the presence of gratings can strongly modify the Casimir force to control the interaction between nanomechanical components.

NEW RESULTS FOR THE CASIMIR INTERACTION: SAMPLE CHARACTERIZATION AND LOW TEMPERATURE MEASUREMENTS

2010 ◽  
Vol 25 (11) ◽  
pp. 2223-2230 ◽  
Author(s):  
R. S. DECCA ◽  
D. LÓPEZ ◽  
E. OSQUIGUIL
Keyword(s):  
Low Temperature ◽  
Resonant Frequency ◽  
Room Temperature ◽  
Casimir Force ◽  
Torsional Oscillator ◽  
Parallel Plates ◽  
Plasma Model ◽  
Sample Characterization ◽  
Proximity Force Approximation ◽  
Coated Surfaces

We describe our latest results in the separation dependence of the Casimir interaction in the sphere-plane geometry for two Au-coated surfaces. All results are obtained by measuring the change in the resonant frequency of a sensitive microelectromechanical torsional oscillator as the separation between the sphere and the plane is changed. By means of the proximity force approximation, the change in resonant frequency yields the Casimir pressure between two parallel plates at the same separation. We present results for a new sample at room temperature, where the dielectric function has been measured in the 190-825 nm range. We show that the results of the Casimir force in this sample and in previous samples are virtually indistinguishable. Furthermore, the observed differences between measured and tabulated optical properties data do not show any effect on the calculation of the Casimir interaction. We also present results of the measurement of the Casimir force between a sphere and a plane at 300, 77, 4.2 and 2.1 K. While low temperature results are noisier than room temperature ones, precluding a direct exclusion of either the Drude or the plasma model, the average of the measurements coincide at all temperatures.

scholarly journals THE CASIMIR EFFECT IN THE SPHERE-PLANE GEOMETRY

2012 ◽  
Vol 14 ◽  
pp. 250-259 ◽  
Author(s):  
ANTOINE CANAGUIER-DURAND ◽  
ROMAIN GUÉROUT ◽  
PAULO A. MAIA NETO ◽  
ASTRID LAMBRECHT ◽  
SERGE REYNAUD
Keyword(s):  
Ambient Temperature ◽  
Casimir Force ◽  
Casimir Effect ◽  
Numerical Results ◽  
Plane Geometry ◽  
Finite Conductivity ◽  
Rich Variety ◽  
Proximity Force Approximation ◽  
Multipolar Expansion

We present calculations of the Casimir interaction between a sphere and a plane, using a multipolar expansion of the scattering formula. This configuration enables us to study the nontrivial dependence of the Casimir force on the geometry, and its correlations with the effects of imperfect reflection and temperature. The accuracy of the Proximity Force Approximation (PFA) is assessed, and is shown to be affected by imperfect reflexion. Our analytical and numerical results at ambient temperature show a rich variety of interplays between the effects of curvature, temperature, finite conductivity, and dissipation.

scholarly journals Demonstration of the asymmetric lateral Casimir force between corrugated surfaces in the nonadditive regime

2009 ◽  
Vol 80 (12) ◽  
Author(s):  
H.-C. Chiu ◽  
G. L. Klimchitskaya ◽  
V. N. Marachevsky ◽  
V. M. Mostepanenko ◽  
U. Mohideen
Keyword(s):  
Casimir Force ◽  
Corrugated Surfaces

CRITICAL STEPS IN DATA ANALYSIS FOR PRECISION CASIMIR FORCE MEASUREMENTS WITH SEMICONDUCTING FILMS

2011 ◽  
Vol 26 (22) ◽  
pp. 3900-3909 ◽  
Author(s):  
A. A. BANISHEV ◽  
CHIA-CHENG CHANG ◽  
U. MOHIDEEN
Keyword(s):  
Data Analysis ◽  
Indium Tin Oxide ◽  
Casimir Force ◽  
High Vacuum ◽  
Force Measurements ◽  
Uv Treatment ◽  
Critical Data ◽  
Ito Film ◽  
Atomic Force ◽  
Gold Sphere

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide ( ITO ) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

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