Progress monitoring of the movement of electrons up to three attosecond – BBC

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An international team of scientists, with the participation of physicists from the Moscow State University named after MV University for the first time in the world was able to prove that it is possible to control quantum processes with an accuracy of several attosecond – one billionth of a billionth of a second. The study published in the latest issue of Nature Photonics journal.

The chemical, physical and biological processes take place extremely rapidly, due torn between atoms and are formed during the numbering in femtoseconds (a millionth of a billionth of seconds). However, if the motion of atoms in a molecule is characterized femtoseconds, the electron dynamics, which determines the chemical bonds takes place a thousand times faster – for periods of time, estimated in the tens and hundreds of attosecond.

In order to study these processes need X-ray free-electron lasers. They generate radiation with a unique combination of properties. In his experiment, Physics neon atoms irradiated by pulses of laser radiation by free electrons is not the same frequency, and at once two harmonics with wavelengths of 63.0 and 31.5 nm, and then watched the direction of emission of photoelectrons from the atom.

By varying the time delay between the harmonics, the researchers followed the dynamics of the process by measuring the change in the shape of the angular distributions of photoelectrons. As a result, by circumstantial evidence they were able to track down that electrons are emitted from the atom with an interval of three attoseconds

«In this work, the first time we managed to implement a scheme which allows to determine the relative phase of the two laser harmonics free electron. – says one of the authors of Elena Gryzlov, a senior researcher at the department of electromagnetic processes and atomic nuclei interactions Research Institute of nuclear physics named after DV Skobel’tsyn MSU. – To suppress or, on the contrary, the allocation of additional frequencies created by a variety of methods, but they do not apply to the high-frequency range of vacuum ultraviolet and X-rays, since there is no conventional lasers mirrors or polarizers. However, the main conclusion that follows from this experiment, probably lies in the fact that it is generally possible in principle -. To control quantum processes with an accuracy of several attosecond »

Scientists have already applied for on FERMI similar experiment more complex than an atom of neon systems – molecules. They propose to study complex phenomena related to the catalytic processes, and atmospheric chemistry

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