Modifying the Casimir force between indium tin oxide film and Au sphere

Abstract

We present complete results of the experiment on measuring the Casimir force between an Aucoated sphere and an untreated or, alternatively, UV-treated indium tin oxide film deposited on a quartz substrate. Measurements were performed using an atomic force microscope in a high vacuum chamber. The measurement system was calibrated electrostatically. Special analysis of the systematic deviations is performed, and respective corrections in the calibration parameters are introduced. The corrected parameters are free from anomalies discussed in the literature. The experimental data for the Casimir force from two measurement sets for both untreated and UVtreated samples are presented. The random, systematic and total experimental errors are determined at a 95% confidence level. It is demonstrated that the UV treatment of an ITO plate results in a significant decrease in the magnitude of the Casimir force (from 21% to 35% depending on separation). However, ellipsometry measurements of the imaginary parts of dielectric permittivities of the untreated and UV-treated samples did not reveal any significant differences. The experimental data are compared with computations in the framework of the Lifshitz theory. It is found that the data for the untreated sample are in a very good agreement with theoretical results taking into account the free charge carriers in an ITO film. For the UV-treated sample the data exclude the theoretical results obtained with account of free charge carriers. These data are in a very good agreement with computations disregarding the contribution of free carriers in the dielectric permittivity. According to the hypothetical explanation provided, this is caused by the phase transition of the ITO film from metallic to dielectric state caused by the UV-treatment. Possible applications of the discovered phenomenon in nanotechnology are discussed.

Constraints on non-Newtonian gravity and light elementary particles from measurements of the Casimir force by means of a dynamic atomic force microscope

“…For dielectric test bodies the theoretical predictions were found in agreement with the data only if the contribution of free charge carriers is omitted [33][34][35][36][37][38]. Keeping in mind that many of the experiments mentioned above were used, first, to make a selection between different theoretical approaches and, second, to constrain corrections to Newtonian gravity from the measure of agreement between the data and the predictions following from a selected approach, the constraints obtained were sometimes claimed to be of dubious merit [39].…”

Casimir interaction at liquid nitrogen temperature: Comparison between experiment and theory

“…[11][12][13][14][15][16] ) and between a metallic and a semiconductor surfaces (see, e.g., Refs. [17][18][19][20][21][22][23][24] ). Quite unexpectedly, the experimental data of many experiments performed at room temperature 13,15,16,18,[23][24][25][26] were found to exclude the theoretical predictions taking into account the relaxation properties of conduction electrons for metals and the contribution of free charge carriers for semiconductors of the dielectric type.…”

“…[17][18][19][20][21][22][23][24] ). Quite unexpectedly, the experimental data of many experiments performed at room temperature 13,15,16,18,[23][24][25][26] were found to exclude the theoretical predictions taking into account the relaxation properties of conduction electrons for metals and the contribution of free charge carriers for semiconductors of the dielectric type. The same data were found to be consistent with theory neglecting the relaxation properties of conduction electrons for metals and the free charge carriers for dielectric-type semiconductors (the two experiments which claim confirmation of the role of relaxation properties of free electrons for metallic test bodies 27,28 are critically discussed in the literature [29][30][31][32] ).…”

How to modify the van der Waals and Casimir forces without change of the dielectric permittivity

“…Another surprise was from the measurements [29,30,50] of the thermal Casimir force at T = 300 K between an Au-coated sphere and an indium tin oxide (ITO) film deposited on a quartz substrate. At room temperature ITO is a good conductor at low frequencies, but is transparent to visible and near infrared light.…”

“…Starting in 1997, a lot of experiments on measuring dispersion forces between bodies made of different materials have been performed using modern laboratory techniques made possible by micro-and nanotechnology (reviews [24,25,26] contain detailed description of all experiments with the exception of the most recent [27,28,29,30,31]). All these experiments measured dispersion forces in the retarded regime, i.e., thermal Casimir forces.…”