Sensitivity and accuracy of Casimir force measurements in air

Abstract

Quantum electrodynamic fluctuations cause an attractive force between metallic surfaces. At separations where the finite speed of light affects the interaction, it is called the Casimir force. Thermal motion determines the fundamental sensitivity limits of its measurement at room temperature, but several other systematic errors contribute uncertainty as well and become more significant in air relative to vacuum. Here we discuss the viability of the force modulation measurement technique in air (compared to frequency modulation, which is typically used in vacuum, and quasi-static deflection, which is usually used in fluid), characterize its sensitivity and accuracy by identifying several dominant sources of uncertainty, and compare the results to the fundamental sensitivity limits dictated by thermal motion and to the uncertainty inherent to calculations of the Casimir force. Finally, we explore prospects for mitigating the sources of uncertainty to enhance the range and accuracy of Casimir force measurements. arXiv:1811.07175v2 [quant-ph]

Recent measurements of the Casimir force: Comparison between experiment and theory

“…1 It turned out that the values of residual potential difference depend on separation which means that, in addition to the Casimir force and well understood electric forces due to the applied potentials, there were some uncontrolled electrostatic forces due to surface patches. 5,9,10 Contrary to many experiments on measuring the Casimir force, 1, 7, 9, 10, 14 the Casimir metrology platform 16 does not provide the means for an independent measurement of the sphere-plate separations. The absolute separations are determined from the fit of the measurement data to two versions of the theory, i.e., to the zero-temperature Casimir force between the ideal metal sphere and plate and to the perturbation expansion of the Casimir force in two small parameters 23 (the relative temperature and relative penetration depth).…”

“…Two of them were devoted to measurements of the Casimir force in a gaseous or liquid media 3,4 (see also Ref. 5 investigating sensitivity and accuracy of Casimir force measurements in air). Several experiments needed for future applications of the obtained results in nanotechnology were devoted to measurements of the Casimir force in an optomechanical cavity, 6 silicon carbide systems, 7 and between silicon nanostructures.…”

Recent progress in engineering the Casimir effect – applications to nanophotonics, nanomechanics, and chemistry

“…For the next two decades, there were no significant experimental advances until the precision measurement of the Casimir effect by Lamoreaux [9] using modern experimental techniques. This measurement ushered in a new wave of Casimir force experiments using a variety of techniques [10,23,24,35,[52][53][54][55][56][57]. Figure 2 gives a brief overview of several experimental achievements pertaining to detecting and modifying the Casimir force with a focus on early experimental techniques and advancements [5][6][7][8][9][10]55], the effect of the material's optical properties [27,32,33,[35][36][37][38][58][59][60], and the effect of surface texturing and geometry [24,26,[28][29][30]61].…”

Phonon Casimir effect in polyatomic systems

“…[1] The smallness of the effect was not exaggerated as it took fifty years of technological development for this interaction to be observed. [2] In recent years, advances in nanotechnology [3][4][5][6][7][8][9][10][11][12] and cold atoms [13][14][15][16] have stimulated the community's interest in this subject [17][18][19][20][21] as the relevant energy scales have become increasingly accessible in the experimental setting.…”