The Nobel Prize in Physics in 2018 was awarded to Arthur Ashkin for optical tweezers and his application in the field of biology, Gerard Mourou and Donna Strickland for developing a method for generating high-intensity ultrashort optical pulses. A live broadcast of the winner’s announcement is conductedon the website of the Nobel Committee. More details about the merits of scientists can be found in the press release of the Nobel Committee.
Optical tweezer (optical tweezer) allows you to capture and move microscopic objects – for example, atoms or living cells – using a laser beam of a special shape. When a microparticle enters the electric field of a laser beam, its charge is redistributed in volume, and an electric dipole moment is induced in it . On the other hand, the energy of a dipole placed in an electric field depends on its orientation – hence, in an attempt to reduce this energy, the microparticle will rotate and “creep” along the field gradient. It turns out that an effective gradient force acts on the particle from the side of the laser. If, however, the laser is focused in such a way that its profile resembles the Gaussian distribution, the gradient of the electric field will be directed to one point, and as a result, the particle will be captured by the laser beam.
“This method is actively used in biology – if you picked up the wavelength so that the particle does not absorb it. For example, you can move a living cell where you need, and the cell does not collapse, remains whole and viable. And it can be placed where you need to within a few hundred nanometers – depending on the wavelength of the laser, “said Dmitriy Chubich, an employee of the 3D printing laboratory for functional microstructures at MIPT, N + 1.
Since then, optical tweezers are actively used to study the processes occurring in living organisms. In particular, with their help, biophysicists measured the viscoelastic properties of biopolymers and learned how to collect artificial cells in ordered structures. In addition, scientists often use optical tweezers to control individual atoms – for example, in March of this year, Australian physicists measured to the nearest hundredths of antonion a force acting on a single atom, and in April the American researchers first conducted a chemical reaction between individual atomsalkali metals. Moreover, optical tweezers have obvious practical applications – in January this year, American engineers received using this technology a color three-dimensional image resembling holograms from science fiction films.
Gerard Moore and Donna Strickland (she became the third woman in history to receive the Nobel Prize in physics after Maria Curie and Maria Göppert-Meyer
“We use them, as a rule, for structuring surfaces. If the pulse lasts a long time, the first edge of the pulse triggers a response in the substance, and the ones following it can neutralize this response. Here everything happens so instantaneously that it strikes, and the response appears in the material, the most pure from the physical point of view. With its help we obtain various plasmonic structures on the surface of matter. These structures can work as antennas, that is, transform radiation on these structures. In particular, it is used to amplify photoluminescence signals, signals of Raman scattering of light, for ultra-sensitive chemical analysis, to create metamaterials, superhydrophobic surfaces, “explained Oleg Vitryk, an employee of the Institute of Automation and Control Processes of Far Eastern Branch of the Russian Academy of Sciences.
Last year, the Nobel Prize in Physics received Rainer Weiss, Barry Barish and Kip Thorne “for a decisive contribution to the LIGO detector and for observing gravitational waves.” Thanks to the work of scientists, astronomers have received yet another channel for observing distant objects. More details about the history and operation of the detector LIGO, as well as the future of gravitational astronomy can be found in our materials “Thinner Proton” and “Behind the Wave Wave” .
In 2016, Nobel Prize laureates in physics became Duncan Haldane, David Thouless and Michael Kosterlitz, who developed the theory of topological phase transitions. The theory, constructed by physicists, predicts that phase transitions may exist in two-dimensional systems, although there is no order parameter in them-this allows one to describe superconductivity, superfluidity, and magnetic ordering in thin layers of materials. More information about the work of scientists can be found in the article “Topologically Protected” .
The size of the Nobel Prize is not fixed, but is determined by the interest from the account of Alfred Nobel – therefore throughout history he constantly fluctuated, although he remained in the region of one million dollars in terms of the current rate. The maximum prizes of the laureates were awarded in 2007 – then the size of one award was about 1.56 million dollars. In 2012, the fund reduced all premiums by 20 percent to avoid a reduction in capital. This year, the premium is 9 million kroons (slightly less than 1 million US dollars at the current rate).