639
42 yoktonyutona
Yoktonyutona 42 or 42 * 10 -24 sup> Newton - force vozdeystvovashaya a cloud of 1200 rubidium atoms cooled to near zero kelvins in the unique experiment , conducted by scientists from Lawrence Berkeley National Laboratory. This is the weakest force ever measured by man. She's four times the theoretical minimum (стандартный quantum limit ), below which no force can not be measured due to the fundamental limitations of quantum mechanics. Previous "record of weakness" (174 yoktonyutona) was raised in 2010.
Experimental scheme shown below. Cloud of rubidium atoms is used as a mechanical oscillator. Atoms are held in an optical trap - between the fronts standing light wave, which is supported by the lasers A and B with a wavelength of 860 and 840 nm. This trap allows to keep the cloud of atoms in the right place, without heating them. Modulating the amplitude of the laser B, you can make the oscillator to oscillate at a certain frequency. Fluctuations recorded on the phase change of the third light wave passing through a cloud. Knowing the mass of the oscillator and the value of its rejection under the influence of an external force, this force can be calculated.
Measurement of small forces is of great practical importance for the development of scientific instruments. New method of measurement can be used in gravitational wave detectors and сканирующих atomic microscopes silovh . Scientists carried out the measurement record, saying that come closer to the standard quantum limit can be, if possible even more cool oscillator and improve the sensitivity of the optical detector.
Source: habrahabr.ru/post/228077/
Experimental scheme shown below. Cloud of rubidium atoms is used as a mechanical oscillator. Atoms are held in an optical trap - between the fronts standing light wave, which is supported by the lasers A and B with a wavelength of 860 and 840 nm. This trap allows to keep the cloud of atoms in the right place, without heating them. Modulating the amplitude of the laser B, you can make the oscillator to oscillate at a certain frequency. Fluctuations recorded on the phase change of the third light wave passing through a cloud. Knowing the mass of the oscillator and the value of its rejection under the influence of an external force, this force can be calculated.
Measurement of small forces is of great practical importance for the development of scientific instruments. New method of measurement can be used in gravitational wave detectors and сканирующих atomic microscopes silovh . Scientists carried out the measurement record, saying that come closer to the standard quantum limit can be, if possible even more cool oscillator and improve the sensitivity of the optical detector.
Source: habrahabr.ru/post/228077/
