Physicists using compressed vacuum were able to circumvent the standard quantum limit.
Physicists from Germany and Italy with compressed vacuum were able to circumvent the standard quantum limit — the limit imposed by quantum mechanics for the measurement process. Dedicated to this Preprint of a study published on the website arXiv.org.
In quantum mechanics the process of measurement of any quantity as a result of interaction with the measuring device it is changing. This imposes restrictions on the measurement accuracy. For example, according to the principle of Heisenberg, it is impossible to simultaneously exactly determine position and momentum.
In their study, the researchers used an atomic Ramsey interferometer. This device measures the phase difference, and includes a resonator in which the interaction of the condensate of Bose-Einstein from ten thousand atoms of rubidium-87 occurs only at the input and the output.
In a classical interferometer, the ensemble of atoms should only be made in one of two States. An idle state is the source of the noise. Scientists were able to reduce this noise. To do this, physicists have used compressed vacuum containing an average of 0.75 of an atom that has improved the measurement sensitivity by 2.05 dB. Compressed vacuum represents a state with extremely low noise, which when measured per unit of time the number of particles tends to a constant value with decreasing observation time. Scientists hope to use the results of research in cryptography.
