These new techniques enable physicists to capture electron movements with light pulses lasting only an attosecond - or one quintillionth of a second - faster than Eadweard Muybridge used when taking photographs at Santa Anita racetrack of horses galloping.
Such small split seconds reveal details previously inaccessible, leading to sharper electron microscopes and early diagnosis tests for diseases.
Ferenc Krausz
One second may seem like an eternity, but for physicists to study electron motion in atoms and molecules they require shorter pulses of light called attosecond pulses; their creators were recently awarded this year's Nobel Prize in physics. Ferenc Krausz of Ludwig Maximilian University Munich and Max Planck Institute of Quantum Optics Garching, Anne L'Huillier from Sweden's Lund University and Pierre Agostini from Ohio State University are being honored for their experimental methods that create nearly unimaginably short pulses, which enable scientists to see inside atoms and molecules during processes previously impossible to track.
Lasers used to generate attosecond pulses produce ultrafast light bursts with an intense electromagnetic field that interacts with electrons in atoms and molecules, leading to sudden increases or decreases in particle energies; the resultant femtosecond pulses contain this information on how electrons are moving at that particular moment, providing key insight into understanding matter-light dynamics.
Krausz's research specializes in nonlinear light-matter interactions and has pioneered ultrashort laser pulses lasting femtoseconds to several hundred attoseconds using chirped multilayer mirrors, making possible the selection and observation of individual pulses lasting just a few wave cycles to study their effects - in particular tracking photoexcitation, the phenomenon by which an electron leaps from orbital into another - an effect which led to some amazing discoveries and developments.
Photoexcitation causes positively charged electrons in an atom or molecule to cohabit two orbitals simultaneously -- creating a quantum mechanical superposition state. When an electron moves from one energy orbital to the next one suddenly, they leave behind an opening detectable with lasers; Krausz was able to use his lasers to observe this hole's pulsed pattern over time.
Anne L’Huillier
Anne L'Huillier was teaching her class when she received news that she had won the Nobel Prize for physics - she tried her best to remain focused while receiving this news; but found it "difficult". L'Huillier became only the fifth woman ever to win such an accolade.
She began conducting experiments in the 1980s that revealed a new phenomenon from laser light's interaction with gaseous atoms, enabling her to create flashes of light much shorter than had been possible before, showing how electrons can be made to behave in specific ways by altering how they move.
Strobe lights have long been used by scientists to observe fast processes, giving them access to an otherwise inaccessible world. If aimed at an extremely fast fan spinning at its fastest speed, each flash illuminates one blade as though frozen in time; similarly this technique can show how electrons travel within materials.
Researchers can use these techniques to observe how an electrical current flows in semiconductors or detect subtle changes in blood cells that could indicate cancer. Furthermore, researchers can use fluoroscopy to study how particles of matter react with one another, opening up an entirely new field of research called attochemistry.
This year's Nobel Prize in physics recognizes experimental physicists who used ultrashort pulses to shed light on electrons that previously lay hidden. According to Mats Larsson, one of the members of the Nobel committee, they could not have accomplished this without significant contributions from theoretical physicists; it demonstrates their strength as fields when there are now laureates from both theoretical and experimental physics fields.
Pierre Agostini
Pierre Agostini of Ohio State University, Ferenc Krausz from the Max Planck Institute of Quantum Optics in Garching and Anne L'Huillier from Lund University all provided humanity with invaluable tools for exploring electrons inside atoms and molecules. Through creating pulses of light that allow observers to view fast electron movement inside materials using lasers that emit photons - these Nobel laureates helped us explore this fascinating universe!
Electrons are key players in our physical world, yet elusive particles. Because of their dual nature as particles and waves, it can be challenging to follow them at an attosecond (one quintillionth or 10-18 of a second).
Scientists have long attempted to use ever-faster lasers to capture atomic action on video, yet existing technologies only lasted about one billionth of an attosecond or femtosecond - not enough time for scientists to observe what occurred at an atom level, let alone larger events such as room renovation or human heartbeats.
But the research of these laureates enabled them to create lasers which produced photons much faster than anyone anticipated. They used it to capture images of fast-moving electrons within substances and demonstrate how to dissect ultrashort photons into their constituent parts for observing atomic motion at levels never seen before. Their discovery represents an extraordinary advance toward understanding physical phenomena that will revolutionize multiple industries. Their persistence shows the immense power of scientific investigation even when it seems hopeless; for Agostini, who found new life after forced retirement from France's nuclear energy commission to begin an impressive career elsewhere, this triumphant moment marks his success all the more hearteningly.
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