(a) Schematic of the isolation system, the vacuum chamber, and the positioning system inside the vacuum chamber. (b) Cut view of the chamber and the probe. (c) Isometric image of the sample mounting subsystem and fiber mounting subsystem.
Casimir sphere and its holder (a) Side-view photograph. (b) Cross-sectional view of the drawing assembly. (c) Perspective view. (d) Isometric view of the drawing.
Fabrication process of the nanomembrane. (a) Bare Si wafer. (b) Deposition of 330 nm LPCVD silicon nitride. (c) CHF3/O2 RIE of silicon nitride (d) Anisotropic KOH etching of silicon. (e) Ebeam evaporation of Au/Ti layer. (f) Optical image of the nanomembrane.
(a) Surface of the cleaved fiber. (b) Schematic diagram of the fiber-optic interferometer and the detection and actuation scheme.
Interferometer output for 45 min record.
(a) Optical image of a nanomembrane with a 36% of the surface covered by gold. (b) Optical image of a nanomembrane with a 12% of the surface covered by gold. (c) Frequency response of a nanomembrane not covered by gold. (d) Frequency response of a nanomembrane fully covered by a layer of gold. (e) Resonance frequency of the nanomembrane vs the amount of the surface covered by a layer of gold. (f) Quality factor of the nanomembrane vs the percentage of gold coverage.
(a) Frequency drift with blind viewports (blue) and with transparent viewports (green). The inset shows a zoom-in of the data. (b) Left axis shows the Allan variance vs the integration time for several drive voltages: 500 μV (red), 10 mV (black), and 50 mV (blue). The right axis shows the equivalent gradient force sensitivity.
(a) Parabolas at different target distances: (blue), (red), (green), and (black). (b) Frequency vs Voltage at a fix distance. The data can be nicely fitted to a parabola. In this measurement χ2 = 1.05. (c) Extracted K p (curvature of the parabola). (d) Extrated Δf 0 which has contributions from the Casimir force and the residual electrostatic force. 10 Inset, the contact potential vs the distance with the sphere.
(a) Measured stiffness of a nanomembrane in N/m. The stiffness at the center is minimum and correspond for this particular sample to 230 N/m. (b) Measured surface potential in Volts. In this sample there is a strong variation of the surface potential across the surface.
Article metrics loading...
Full text loading...