The 2023 Nobel Prize in Physics has been awarded to France’s Pierre Agostini, Hungarian-Austrian Ferenc Krausz and French-Swedish Anne L’Huillier for experimental methods that generate attosecond pulses of light (10-18 seconds) for the study of electron dynamics in matter.
In our daily lives, we often miss observing fast-paced processes entirely. For instance, when a bullet strikes an apple, we witness the aftermath—a shattered apple—but fail to perceive the entire event, which lasts mere milliseconds. However, with a camera equipped with a high shutter speed, every phase of the bullet penetrating and exiting the apple, ultimately destroying it, becomes visible.
At the atomic and subatomic levels, phenomena like electron movement or energy dynamics occur at astonishing speeds—mere picoseconds (10-12 seconds) or femtoseconds (10-15 seconds). To scrutinize these events, scientists rely on ultra-short pulses of light, akin to using exceptionally high shutter-speed cameras.
Existing Challenges at the Subatomic Scale:
Observing any process mandates measurements quicker than the rate of change. Although light pulses are indispensable for capturing atomic-level processes, they cannot infinitely shorten. Light, composed of electromagnetic field vibrations, necessitates pulses at least one cycle long, equivalent to its wavelength.
Enter attoseconds science:
Femtosecond pulses (10-15 seconds) permitted scientists to witness atomic or molecular-level processes. However, at the subatomic level, particle dynamics unfold even faster—on the scale of attoseconds (10-18 seconds). For instance, electron dynamics outpace those of atoms by 100 to 1000 times due to lower inertia.
The previously used femtosecond pulses exceeded the rapid subatomic motion, making the production of shorter, attosecond-range pulses seemingly impossible. Consequently, scientists were unable to glimpse electron motion with existing technologies, relegating femtosecond “photography” as the perceived limit.
Nobel-Winning Research:
Pioneering scientists facilitated the observation of attosecond-scale phenomena by creating ultrashort pulses of light (10-18 seconds). Independently, they developed experimental methods, leveraging mixed wavelengths to generate attosecond light pulses. These pulses enable the exploration of electron dynamics within matter, offering insights into rapid subatomic changes and the ability to influence processes by adjusting intermediate steps.
Potential Applications:
In Electronics: Understanding and controlling electron behavior in materials aids in designing more efficient electronic devices.
In Medicine: Attosecond pulses can revolutionize medical diagnostics by identifying different molecules and studying molecular-level changes in blood, facilitating disease detection.