Pierre Agostini, Ferenc Krausz and Anne Lhuillier received the Nobel Prize in Physics for their ability to track electrons

The 2023 Nobel Prize in Physics was awarded “for experimental methods that generate attosecond pulses of light to study the dynamics of electrons in matter.” The award of 11 million Swedish kronor (about $1 million) will be shared equally by physicists Pierre Agostini (Ohio State University, USA), Ferenc Krausch (Max Planck Institute for Quantum Optics, Germany) and Ann Lhuille (Lund University, Sweden). The work of the laureates “gave humanity new tools for exploring the world of electrons inside atoms and molecules,” the Nobel Committee explained. This will make it possible to create virtually new branches of applied physics or chemistry, experts believe.

Nobel Prize in Physics awarded 82-year-old professor at Ohio State University (USA) Pierre Agostini, 61-year-old director of the Max Planck Institute for Quantum Optics (Germany) Ferenc Krausch and 65-year-old professor at Lund University (Sweden) Ann Lüje. Their experiments resulted in light pulses so short that they must be measured in attoseconds (a unit of time equal to 1 in 10 to the minus 18th power of a second). This “gives humanity new tools to explore the world of electrons inside atoms and molecules,” the Nobel committee explained. “If we want to study truly short-term events, we need special technology.”

The basis for the scientific discovery was laid by Anne Lhuillier. In 1987, she passed light through an inert gas and discovered that the properties of the infrared laser beam changed. This was caused by the interaction of the beam’s photons with atoms – some electrons gained energy by re-emitting it in the form of light. Based on this, Pierre Agostini managed in 2001 to create and study a series of sequential light pulses – each of them lasted only 250 attoseconds. At the same time, Ferenc Krausz was able to isolate a single light pulse with a duration of 650 attoseconds.

The contribution of the laureates made it possible to study processes that occur so quickly that previously it was impossible to follow them, the Nobel Committee explains. “Now we can open the door to the world of electrons. Attosecond physics gives us the opportunity to understand the mechanisms that govern electrons. The next step will be to use them,” said Eva Olsson, chair of the Nobel Physics Committee.

Sergei Popruzhenko, head of the Department of Theoretical Nuclear Physics at National Research Nuclear University MEPhI, explains: thanks to the work of new Nobel laureates, experimental physicists have learned to control in real time the processes that occur in atoms and molecules with electrons.

“To put it simply, they learned to see the movement of an electron in an atom. This makes it possible to create virtually new sections of applied physics or chemistry – attophysics and attochemistry. That is, the physics and chemistry of processes lasting attoseconds,” says the scientist.

This branch of experimental science will make it possible to explore in a new way those fundamental effects that have long been known, for example, the Auger effect (a single electron ejected from an atom). In the future, this may have practical significance: “When the technique of using attosecond laser pulses develops even further, it will be possible to control processes not only in atoms and molecules, but also in solids. This means also in semiconductor-based devices that use ultra-fast processes.”

Director of the Center for Quantum Metamaterials at MIEM NRU HSE Alexey Vagov notes that the study of short pulses is one of the most popular areas of modern physics: “Over the past ten years it has become cutting-edge, scientists around the world are trying to look inside the atom.” The scientist emphasizes that in 2018 “half of the prize was taken by Gerard Mourou and Donna Strickland, who developed a method for generating femtosecond petawatt laser pulses” – work in the same field, but at a different level.

“Research of this scale requires expensive equipment and a large scientific base, so it is not feasible within one country,” says Mr. Vagov.

He recalled that until 2022, Russia was an active participant in the European X-ray Free Electron Laser consortium (Hamburg), where such experiments in laser physics were possible, but after the entry of Russian troops into Ukraine, cooperation was stopped.

The Nobel Prize presentation will take place on December 10 in Stockholm: the laureates will share 11 million Swedish kronor (approximately $1 million). Let us recall that in 2022 the physics award went to the French and American physicists Alain Aspe and John Clauser, as well as the Austrian scientist Anton Zeilinger for “experiments with entangled photons, when two separated particles behave as a single whole,” which made it possible to conduct research with quantum computers and networks.

Polina Yachmennikova