Nobel Prize in Physics 2023

The 2023 Nobel Prize for Physics was shared by three scientists—Pierre Agostini, Ferenc Krausz and Anne L’Huillier—for their “experimental methods that generate attosecond pulses for the study of electron dynamics in matter.”
Anne L’Huillier became the fifth woman to win the Physics Nobel Prize.

Seeing electrons: Why it was challenging

Electrons are negatively charged particles within atoms, and their rapid movement posed challenges for direct observation.
Electrons’ ultra-fast dynamics required exposure times in the order of attoseconds (10^-18 seconds) for clear observation.
Atom movements can be studied with femtosecond pulses (10^-15 seconds), but electrons interact even faster in the attosecond realm (10^-18 seconds).
Traditional femtosecond pulses were previously considered the limit for studying atomic and molecular processes.
The attosecond pulses of light allow scientists to observe processes at the atomic and subatomic levels with unprecedented speed and precision.

Creating Shorter Light Pulses

In 1987, Anne L’Huillier’s team passed an infrared laser beam through a noble gas, producing overtones with wavelengths as fractions of the beam.
Ultraviolet light overtones were created, and they interacted with each other through constructive and destructive interference.
Fine-tuning the setup allowed the creation of intense attosecond light pulses due to constructive interference.

Attosecond Pulse Development

In 2001, Pierre Agostini’s group successfully produced a series of 250-attosecond light pulses.
Ferenc Krausz’s team in Austria developed a technique to separate individual 650-attosecond pulses from a pulse train.
Further, Agostini, Krausz, and L’Huillier developed innovative methods, including mixing light of different wavelengths, to produce attosecond pulses of light.
These developments enabled rapid experiments to measure the energy of released electrons.

Applications of Attosecond Physics

Attosecond pulses can capture images of short-lived atomic and molecular processes.
Attosecond science has potential applications in electronics, medicine (especially cancer therapy), physics, chemistry, and biology.
Researchers aim to use attosecond science to control and manipulate processes for desired outcomes.

An attosecond is an incredibly brief unit of time, equivalent to one quintillionth (10^-18) of a second.
To put this in perspective, if you were to stretch one second to cover the entire age of the universe, approximately 13.8 billion years, an attosecond would be just a fraction of that second.
Attoseconds are now being harnessed by physicists to probe and manipulate fundamental aspects of our physical world.
At this timescale, researchers can capture the rapid dynamics of electrons within atoms and molecules, providing insights into chemical reactions and electronic behavior.
Attosecond science allows for the creation and manipulation of extreme ultraviolet (XUV) and X-ray pulses, which are essential for imaging ultrafast processes at the atomic and molecular scale.
These attosecond pulses enable scientists to observe the quantum mechanical nature of electrons and their interactions with atomic nuclei, with profound implications for fields such as chemistry, materials science, and technology development.

AMIGOS IAS