Attosecond

From HandWiki
Short description: One quintillionth of a second

An attosecond (abbreviated as as) is a unit of time in the International System of Units (SI) equal to 10−18 or 1⁄1 000 000 000 000 000 000 (one quintillion) of a second.[1] An attosecond is to a second as a second is to about 31.71 billion years.[2] The attosecond is a newly discovered "slice of time" that is tiny but has various potential applications: it can observe oscillating molecules, the chemical bonds formed by atoms in chemical reactions, and other extremely tiny and extremely fast things.

Common measurements

  • 0.247 attoseconds: travel time of a photon across "the average bond length of molecular hydrogen"[3]
  • 24 attoseconds: the atomic unit of time[4]
  • 43 attoseconds: the shortest pulses of laser light yet created[5]
  • 53 attoseconds: the shortest electron laser pulse ever created [6][7]
  • 53 attoseconds: the second-shortest pulses of laser light created[8][9]
  • 82 attoseconds (approximately): half-life of beryllium-8, maximum time available for the triple-alpha process for the synthesis of carbon and heavier elements in stars[10]
  • 84 attoseconds: the approximate half-life of a neutral pion
  • 100 attoseconds: fastest-ever view of molecular motion[11]
  • 320 attoseconds: the estimated time it takes electrons to transfer between atoms[12][13]

Historical development

In 2001, Ferenc Krausz and his team at the Technical University of Vienna fired an ultrashort wavelength (7 femtoseconds) red laser pulse into a stream of neon atoms, where the stripped electrons were carried by the pulse and almost immediately re-eject into the neon nucleus.[14]

While capturing the attosecond pulse, the physicists also demonstrated its utility. They aimed attosecond and longer-wavelength red pulses at a type of krypton atom simultaneously: first, the electrons were knocked off; then, the red light pulse hit the electrons; finally, the energy was tested. Judging from the difference in the timing of these two pulses, the scientists obtained a very precise measurement of how long it took the electron to decay (how many attoseconds). Never before have scientists used such a short time scale to study the energy of electrons.[15]

Applications

Need for more precise units

The crystal lattice vibrates and molecules rotate on a scale of picoseconds. The creation and breaking of chemical bonds and molecular vibration happen in femtoseconds. Observing the motion of electrons happens on the attosecond scale.[16]

The number of electrons in an atom and their configuration define an element. Because attosecond pulses are faster than the motion of electrons in atoms and molecules, attosecond provides a new tool for controlling and measuring quantum states of matter.[17] These pulses have been used to explore the detailed physics of atoms and molecules and have potential applications in fields ranging from electronics to medicine.[18]

Directly observing the wave oscillations of light

Using a method called attosecond streaking, people can see the electrical components of EM waves. Scientists start with a gas of neon atoms and ionize them with a single ultrashort burst of UV radiation measured in attoseconds. The electric field of the infrared can then strongly influence the motion of the electrons. The electrons will be forced up and down as the field oscillates. Depending on when the electron is released, this process will emit different final energies. The final measurement of the electron's energy, as a function of the relative delay between the two pulses, clearly shows the traces of the electric field of the attosecond pulse.[19]

See also

References

  1. ↑ "attosecond - Memidex dictionary/thesaurus". 2019-04-07. http://www.memidex.com/attosecond. 
  2. ↑ "Exploring "Attosecond" Time - Steacie Institute for Molecular Sciences (SIMS)". 2007-11-11. http://steacie.nrc-cnrc.gc.ca/personal/corkum/atto5_e.html. 
  3. ↑ Grundmann, Sven; Trabert, Daniel; Fehre, Kilian; Strenger, Nico; Pier, Andreas; Kaiser, Leon; Kircher, Max; Weller, Miriam et al. (2020-10-16). "Zeptosecond birth time delay in molecular photoionization" (in en). Science 370 (6514): 339–341. doi:10.1126/science.abb9318. ISSN 0036-8075. PMID 33060359. Bibcode: 2020Sci...370..339G. https://www.sciencemag.org/lookup/doi/10.1126/science.abb9318. 
  4. ↑ "CODATA Value: atomic unit of time". https://physics.nist.gov/cgi-bin/cuu/Value?aut. 
  5. ↑ "Optica Publishing Group". https://opg.optica.org/oe/viewmedia.cfm?uri=oe-25-22-27506&html=true. 
  6. ↑ Kim, H. Y.; Garg, M.; Mandal, S.; Seiffert, L.; Fennel, T.; Goulielmakis, E. (January 2023). "Attosecond field emission" (in en). Nature 613 (7945): 662–666. doi:10.1038/s41586-022-05577-1. ISSN 1476-4687. PMID 36697865. 
  7. ↑ "Attosecond electron pulses are claimed as shortest ever" (in en-GB). 2023-02-17. https://physicsworld.com/a/attosecond-electron-pulses-are-claimed-as-shortest-ever/. 
  8. ↑ Li, Jie; Ren, Xiaoming; Yin, Yanchun; Zhao, Kun; Chew, Andrew; Cheng, Yan; Cunningham, Eric; Wang, Yang et al. (2017-08-04). "53-attosecond X-ray pulses reach the carbon K-edge" (in en). Nature Communications 8 (1): 186. doi:10.1038/s41467-017-00321-0. ISSN 2041-1723. PMID 28775272. Bibcode: 2017NatCo...8..186L. 
  9. ↑ "Watching quantum mechanics in action: Researchers create world record laser pulse" (in en). https://www.sciencedaily.com/releases/2012/09/120904150100.htm. 
  10. ↑ "Beryllium-8" (in en), Wikipedia, 2023-06-21, https://en.wikipedia.org/w/index.php?title=Beryllium-8&oldid=1161298590, retrieved 2023-10-24 
  11. ↑ "Fastest view of molecular motion" (in en-GB). 2006-03-04. http://news.bbc.co.uk/2/hi/science/nature/4766842.stm. 
  12. ↑ "Electron timed hopping between atoms | New Scientist". 2016-05-11. https://www.newscientist.com/article/dn7700-electron-timed-hopping-between-atoms/. 
  13. ↑ Föhlisch, A.; Feulner, P.; Hennies, F.; Fink, A.; Menzel, D.; Sanchez-Portal, D.; Echenique, P. M.; Wurth, W. (2005-07-01). "Direct observation of electron dynamics in the attosecond domain". Nature 436 (7049): 373–376. doi:10.1038/nature03833. ISSN 0028-0836. PMID 16034414. Bibcode: 2005Natur.436..373F. https://ui.adsabs.harvard.edu/abs/2005Natur.436..373F. 
  14. ↑ "Attosecond Physics becomes a Milestone" (in en). https://www.mpq.mpg.de/4857719/10_05_17. 
  15. ↑ Krausz, Ferenc (2016). "The birth of attosecond physics and its coming of age". Physica Scripta 91 (6). doi:10.1088/0031-8949/91/6/063011. Bibcode: 2016PhyS...91f3011K. https://iopscience.iop.org/article/10.1088/0031-8949/91/6/063011/meta. 
  16. ↑ "The Nobel Prize in Chemistry 1999" (in en-US). https://www.nobelprize.org/prizes/chemistry/1999/press-release/. 
  17. ↑ Canada, National Research Council (2017-06-15). "Importance of attosecond research". https://www.canada.ca/en/national-research-council/news/2017/06/importance_of_attosecondresearch.html. 
  18. ↑ "The Nobel Prize in Physics 2023" (in en-US). https://www.nobelprize.org/prizes/physics/2023/press-release/. 
  19. ↑ Goulielmakis, E.; Uiberacker, M.; Kienberger, R.; Baltuska, A.; Yakovlev, V.; Scrinzi, A.; Westerwalbesloh, Th.; Kleineberg, U. et al. (2004-08-27). "Direct Measurement of Light Waves" (in en). Science 305 (5688): 1267–1269. doi:10.1126/science.1100866. ISSN 0036-8075. PMID 15333834. Bibcode: 2004Sci...305.1267G. https://www.science.org/doi/10.1126/science.1100866. 



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