A team of American and Australian physicists have used the Casimir effect to hold and move a thin membrane. The effect is the attraction of two conductive bodies in a short distance due to fluctuations of virtual and thermal photons. Scientists have learned to use this phenomenon to control the voltage and quality factor of thin plates. In the future this potentially will help to create tools for remote control systems resonators without the introduction of energy losses. Article published in the journal Nature Physics.
According to quantum field theory, in our world there is no absolute vacuum. Even if you somehow completely get rid of matter in some region of space, there will continuously be born and to disappear, pairs of virtual particles and antiparticles. Such a phenomenon is accompanied with fluctuations associated with these particle fields, including elektromagnitnykh, whose quanta are the photons. At any point of the space of continuously appearing and disappearing virtual photons of arbitrary frequencies, but their range can limit. So, between two parallel conducting plates can only be born a virtual photon, whose frequency corresponds to the length of the standing wave between the plates. While outside the plates there is no such restriction, so a virtual photon there will be more. Therefore, the pressure of these quanta of the electromagnetic field on the outer sides of the plates will exceed the pressure on the inside, causing the conductors will be attracted. This effect in 1948, was opened by Dutch physicist Hendrik Casimir.
Later this effect is theoretically generalized to bodies of arbitrary shape and dielectric constant, but sufficiently accurate experiments to test the predictions of Casimir managed to put only in 1997. Recently it became known about the confirmation of theoretically predicted thermal effect of the Casimir — like phenomena that can be observed at nonzero temperatures. It is not because of the birth and disappearance of virtual particles, but because of the very real thermal photons. They, in turn, as in the classical Casimir effect, give rise to fluctuations of the electromagnetic field, but the nature of these oscillations is already non-quantum and thermal.
Now there are more and more indications that the Casimir force can be a very useful tool for physicists. So, Jacob pate (Pate Jacob) from the University of California have proposed a way to study the Casimir effect with the help of a microwave resonator and its application to changes in the mechanical properties of thin conductive membranes. To investigate the Casimir force, pate and his colleagues placed a thin membrane of silicon nitride with a metal-coated near the plate of the microwave resonator at a distance of about a micrometer. This distance directly affects generated by the resonator frequency, which was used as a sensitive indicator of the membrane. The smaller the gap between the membrane and plate resonator — the stronger the Casimir force that pulls the membrane to the resonator. That is its value tried to determine the researchers placed above the membrane electrode, which was drawn this thin plate in contrast to the Casimir force. The reaction of the membrane to the force of gravity of the electrode, the researchers could say how much the Casimir effect holds it in the initial position.