The international group of scientists under the leadership of physicists of the Massachusetts Institute of Technology managed to translate a huge object in almost a pure quantum state, suppressing the movement created by the environment. This object was the system of resonators of the LIGO gravitational and wave observatory. The results of an unusual experiment are published in the SCIENCE journal.
Quantum system can reach the main state in which thermal oscillations (phonons) of atoms are eliminated, during cooling almost to absolute zero. However, this has been done only for tiny objects of nanometer size, for example, clouds of millions of atoms weighing several picograms. Make a transition to a clean quantum state for macroscopic objects, the size of which is comparable to the size of a person, technically difficult.
In the course of a new experiment, scientists used suspended mirrors of a gravitational and wave observatory with a giant laser interferometer (LIGO). The Advanced Ligo Observatory consists of a Michelson interferometer pair, each of which is a channel (shoulder) four kilometer long with vacuum inside. Quartz mirrors, the mass of each of which reaches 40 kilograms, form optical resonators of the Fabry Pen. When a gravitational wave passes through LIGO, the distance between the pendulum mirrors changes (one shoulder is shortened, the other is extended), which is registered by detectors as fluctuations in optical radiation power. The joint movement of each pair of mirrors and two oscillators, in general, can be mathematically considered as one object, namely a mechanical oscillator with a weighing of ten kilograms.
The measurement process itself may accidentally bring the mirror in motion – this phenomenon is called a quantum reverse action of measurement. Photons reflecting from the mirror. To collect information about its movement, the pulse of the mirror is transmitted, creating an error upon subsequent dimension. To compensate this effect, scientists have created a control circuit that applies electrostatic force to mirrors using gold electrons under 400 volts. As a result of suppressing the reverse action of the mirror, no more than one thousandth of the proton size was shifted (less than 10 per minus of the 20th degree of meter).
The remaining oscillation energy corresponded to 77 nanocelvins, which is very close to the calculated temperature of the main state of the oscillator, equal to 10 nanochelvinam. Thus, scientists managed to increase the mass of the object, whose condition was prepared almost to pure quantum. According to researchers, the transformation of the LIGO Observatory into a massive quantum system opens up new opportunities to accurately measure the effects of gravity.