The Royal Swedish Academy of Sciences, Stockholm, Sweden, announced the winners of the Nobel Prize in Physics for the year 2023 on October 3, 2023. This prestigious award has been bestowed on three scientists—Anne L’Huillier, Pierre Agostini, and Ferenc Krausz—for their pioneering work in the field of the study of electrons. The work of these scientists is not only limited to the realm of physics, but has universal significance. Sub-atomic particles, called electrons, play crucial roles in a variety of areas, such as electricity and magnetism. Their work on electrons has made it easier to observe electrons, which has potential applications in the field of diagnosing diseases and developing electronic gadgets. It has paved the way to create extremely short pulses of light that could measure the rapid processes in which electrons move or change energy.
Why Electrons Matter
An atom consists of a nucleus based on protons and neutrons surrounded by an electromagnetically-bound cloud of electrons. It is nearly impossible to observe the real-time movement of electrons as they move very swiftly. Changes in electrons usually take place in a few tenths of an ‘attosecond’. (An attosecond is one billionth of a billionth of a second, which is 1 × 10–18 of a second). The ability to generate attosecond pulses of light has opened the door to the world of electrons and why electrons do matter is because that is “how the atoms bind together”. The importance of the study of electrons in our everyday life is explained by Krausz, “Electrons are, even if we can’t see them, Omnipresent in our life—our biological life and also our technical life, in our everyday life”.
Significance of the Work
The Nobel laureates, through their experiments, have developed short pulses of light which could be measured in attoseconds. Their discovery would help study the fleeting dynamics of electrons in physical matter, which was not possible earlier. The attosecond pulses have also sparked a revolution in the science of light waves called photonics.
The quick pulses, for the first time, allowed the scientists to correlate the timescale of their observations to the natural, swift timescales at which electron dynamics used to occur. The laureates had been working for decades for this significant innovation in laser science and engineering.
The mechanisms that are governed by electrons could be understood in a better way through attosecond physics. Understanding better movement of electrons and their transmission of energy could also help in the creation of more efficient electronic gadgets. It could lead to ultra-fast switching which could lead to the development of rapidly working electronics.
This could be very useful in the study of previously unknown physical phenomena in different types of material. Medical diagnostics could also become better with the use of attosecond pulse science. By exposing a blood sample to a very fast pulse of light, scientists would be able to detect minute variations in the molecules of that sample. This may pave the way to better diagnostics, including cancer.
Contribution by Anne L’Huillier
Anne L‘Huillier (born in 1958) got her Ph.D. from the University Pierre and Marie Curie, Paris, in 1986. She is a professor of atomic physics at the Lund University, Sweden.
Anne L‘Huillier observed, in 1987, that when a beam of laser is passed through a noble gas, it interacts with the atoms to produce some electrons with extra energy, which is then emitted as light. This interaction could be used to produce pulses of ultraviolet light that were each a few hundred attoseconds long. Since then, she had been continuously exploring this phenomenon, which laid the foundation for subsequent breakthroughs.
Contribution by Pierre Agostini
Pierre Agostini (born in 1941) got his Ph.D. in 1968 from Aix-Marseille University, France, and is working as Emeritus professor at the Ohio State University, Columbus, USA.
In 2001, Pierre Agostini succeeded in producing and investigating a series of consecutive light pulses. Each consecutive light pulse lasted just for 250 attoseconds. This produced a series of consecutive light pulses, like a train with carriages. This phenomenon came to be known as the reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) technique.
Contribution by Ferenc Krausz
Ferenc Krausz (born in 1962) received his Ph.D. in 1991 from the Vienna University of Technology, Austria. He is working as a director at the Max Planck Institute of Quantum Optics and as a professor of experimental physics at the Ludwig Maximilian University of Munich, Germany.
Ferenc Krausz worked on a technique that could select a single pulse. His experiment made it possible to isolate a single light pulse that lasted for 650 attoseconds. These brief flashes of light can be used to form images of what is occurring inside atoms and molecules.
The foundation, laid by Pierre Agostini and Ferenc Krausz through their approaches, has formed the basis for much of the attosecond research, carried out presently.
About Nobel Prize in Physics
The Nobel Prize in Physics is awarded, as per the will of Alfred Nobel, “to those who, during the preceding year, have conferred the greatest benefit on mankind” in the field of physics by the Royal Swedish Academy of Sciences, Stockholm, Sweden. This prize is given to promote the sciences and strengthen their influence in the society. The prize carries a cash award of 11 million Swedish Kronor (US$ 1 million). This money is drawn from the inheritance left by Alfred Nobel, who died in 1896.
The prize amount would be shared equally between the three laureates on December 10, 2023.
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