A drop of olive oil led to the discovery of a new universal law of phase transitions. A study by scientists from the Netherlands Research Institute AMOLF is published in the journal Physical Review Letters.
The Interactive Photon Research Group at AMOLF studies non-linearity and noise in photon systems. One of these systems is a cavity, which is formed by two mirrors facing each other at a close distance. Inside this cavity, light is repeatedly reflected from the mirrors in both directions. It turned out that placing an object inside such an optical resonator changes the properties of the system.
Physicist Said Rodriguez and his students Zou Gan and Kevin Peters analyzed the properties of light transmission, increasing and decreasing the distance between two mirrors. They found that the amount of light passing through the cavity depends on the direction of movement of the mirrors.
“The transmission of light through a cavity is non-linear. At a certain distance between the mirrors, the amount of transmitted light depends on whether we open the cavity or close it. This behavior is called hysteresis. It is also observed at certain phase transitions, for example, in boiling water or magnetic materials”.
Dr. Said Rodriguez.
However, in a cavity with olive oil, hysteresis is not always present. At a high rate of change in the direction of the mirrors, the hysteresis disappeared, although according to the equation, this indicator should remain unchanged, despite the rate of change.