archive-edu.com » EDU » C » COLORADO.EDU

Total: 304

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • Reconstruction | JILA-PFC
    teal lilac and purple structures along the driving laser beam wide red line The amazing thing about this work is that the researchers accomplished it without lenses mirrors or other devices used to measure visible light Because optical devices don t work with EUV light the team had come up with a unique way to reconstruct the new complex light field investigating the properties of photoelectrons generated from a copper surface by the extremely complex light field Thus in this seminal work the team pioneered the generation of extremely complex light fields and developed a novel way to accurately measure those fields The researchers were first able to make circularly polarized EUV bursts using high harmonic generation HHG Next they came up with a clever way of transferring the information about the circularly rotating EUV light onto photoelectrons which can be measured For this they irradiated a copper surface yellow with the circularly polarized EUV bursts a process that kicked out photoelectrons green from the surface If the surface is also illuminated with an infrared laser pulse red left at the same time the laser field can wiggle the photoelectrons liberated by the EUV light By looking at those wiggling electrons we observed that the electrons liberated by slightly different bursts of EUV light come out at slightly different times Margaret Murnane said And if we move the EUV and laser light waves by a very small amount by less than a wavelength of visible light we can rotate the direction of the circular EUV field just like rotating the arms in a clock This allows us to collect photoelectrons as we rotate the EUV polarization and know everything about the most complex coherent light pulse generated to date The rotation of the circular EUV field allowed the researchers to

    Original URL path: http://jila-pfc.colorado.edu/highlights/reconstruction (2016-04-29)
    Open archived version from archive

  • Creative Adventures in Coupling | JILA-PFC
    cold neutral atoms behave as charged particles it will be possible to better understand the behavior of electrons in solids something that is essential for developing improved quantum materials and technologies such as spintronic devices which use spins rather than electric charge to carry information Additionally an in depth understanding of spin orbit coupling is necessary for advancing our fundamental understanding of modern quantum science A new theory study by the Rey group has outlined the many advantages of the Ye group s Sr lattice clock for experimental spin orbit coupling studies The clock consists of individual two dimensional pancake layers of about 10 100 identical Sr atoms However the atoms in different pancakes are not identical because the clock laser talks to them differently After talking with the laser pancakes of identical atoms differ from one another in phase As a result if individual Sr atoms tunnel from one layer to another they can readily be identified as different and will collide as nonidentical quantum particles Any frequency differences associated with their energy and motional states can be detected with the exquisitely stable clock laser However quantum tunneling doesn t normally happen in the clock because the layers of atoms are held inside a deep lattice With this understanding in mind the theoretical study laid out an approach for using the Sr lattice clock to better understand spin orbit coupling First by decreasing the lattice depth it would be possible for atoms to tunnel between the layers At the same time the clock laser would be able to drive the atoms between different electronic states Together these two processes would cause the atoms to move in a circular pattern emulating the circular motion of charged electrons in a magnetic field Second the theorists predicted that spectroscopy performed with the

    Original URL path: http://jila-pfc.colorado.edu/highlights/creative-adventures-coupling (2016-04-29)
    Open archived version from archive

  • Back to the Future: The Ultraviolet Surprise | JILA-PFC
    to this breakthrough include Tenio Popmintchev graduate students Dimitar Popmintchev and Christopher Mancuso former research associates Carlos Hernández García Franklin Dollar and Ming Chang Chen former student assistant Amelia Hankla Fellows Agnieszka Jaron Becker Andreas Becker Margaret Murnane and Henry Kapteyn The JILA team collaborated with colleagues from the University of Salamanca Spain National Tsing Hua University Taiwan Cornell University Temple University and Lawrence Livermore National Laboratory For Tenio Popmintchev and the Kapteyn Murnane group the success of their new HHG experiment was a Back to the Future moment The process of high harmonic generation in gases was discovered using UV lasers nearly 28 years ago But because scientists at that time didn t fully understand how to make this process efficient attention turned to using longer wavelength lasers for HHG In fact for many years most scientists believed that producing soft x ray harmonics with UV lasers would be impossible As it turned out it was not impossible Instead it was the ultraviolet surprise In the very first experiments they had driving UV lasers with much longer pulse durations Tenio Popmintchev explained Now as the laser technology has advanced we can make very high energy driving lasers with pulse durations that are an order of magnitude shorter This is what it takes to produce x ray harmonics in this regime Knowing this Tenio Popmintchev was able to build the right UV laser for the job Once the new laser was operational the researchers discovered that it extended the reach of HHG well beyond what they expected And the process occurred in a very different way than with a mid IR driving laser The conversion of mid IR laser light into x ray light requires gently ionized atoms to add the radiation from all atoms constructively In contrast the conversion

    Original URL path: http://jila-pfc.colorado.edu/highlights/back-future-ultraviolet-surprise (2016-04-29)
    Open archived version from archive

  • Dancing to the Quantum Drum Song | JILA-PFC
    The Lehnert group and Steve Burrows JILA In the future quantum microwave networks may handle quantum information transfer via optical fibers or microwave cables The evolution of a quantum microwave network will rely on innovative microwave circuits currently being developed and characterized by the Lehnert group Applications for this innovative technology could one day include quantum computing converters that transform microwave signals to optical light while preserving any encoded quantum information and advanced quantum electronics devices In recent work the group demonstrated that a flexible aluminum drumhead embedded in a microwave circuit made it possible for researchers to manipulate the timing and shape of microwave signals while preserving their quantum nature The oscillating drumhead yellow in the picture is actually part of the microwave circuit s capacitor whose two charge conducting surfaces are just 40 nm apart The capacitor s job is to accumulate and hold electrical charge The dc electrode red in the picture allows the researchers to adjust the capacitor which in turn allows them to change the circuit s resonant frequency making it possible to connect the circuit to other microwave quantum devices The drumhead s job is to encode the quantum information in the microwave signal as mechanical motion and store the quantum information intact until the drumhead s mechanical motion can be reconverted back into microwave radiation After reconversion the researchers verified that the quantum information had indeed come through in good shape We ve learned how to manipulate the information in a microwave signal in a unique way explains graduate student Adam Reed We do this by taking the energy in a propagating electrical signal and transferring it into a drum that s vibrating at megahertz frequencies even though our electrical signal is vibrating at gigahertz frequencies Reed s collaborators on this amazing project

    Original URL path: http://jila-pfc.colorado.edu/highlights/dancing-quantum-drum-song (2016-04-29)
    Open archived version from archive

  • Matt Norcia Wins JILA Scientific Achievement Award | JILA-PFC
    Published 02 19 2016 Dr James Thompson stands next to graduate student Matt Norcia who won a JILA Scientific Achievement Award for building a strontium cavity QED experiment from scratch Graduate Student Matt Norcia Thompson group received a JILA Scientific Achievement Award on February 18 The announcement took place during a special snack time in the Sunrise Room of the JILA Tower Norcia was cited for building a strontium cavity

    Original URL path: http://jila-pfc.colorado.edu/news/matt-norcia-wins-jila-scientific-achievement-award (2016-04-29)
    Open archived version from archive

  • Jun Ye Selected for 2015 Presidential Rank Award | JILA-PFC
    Outreach News Research Highlights Center News JILA PFC Search form Search Advanced Other JILA Sites JILA Home Jun Ye Selected for 2015 Presidential Rank Award Back to News Published 12 16 2015 Jun Ye President Obama has selected JILA Fellow Jun Ye of NIST s Quantum Physics Division to receive a 2015 Presidential Rank Award The award cited Ye s work advancing the frontier of light matter interaction and focusing on precision measurement quantum physics and ultracold matter optical frequency metrology and ultrafast science The Presidential Rank Awards honor a select group of senior Federal employees for sustained extraordinary accomplishment These employees are strong leaders professionals and scientists who achieve results and consistently demonstrate strength integrity industry and a relentless commitment to excellence in public service Ye was awarded the highest of the two Rank Award levels the Distinguished Executive which can be given to no more than 1 of the approximately 6 800 senior Federal employees across the nation The Award includes a monetary prize equal to 35 of the employee s base pay plus a certificate signed by the President The award recognizes Ye as a world leader in laser and atomic physics He has a long and

    Original URL path: http://jila-pfc.colorado.edu/news/jun-ye-selected-2015-presidential-rank-award (2016-04-29)
    Open archived version from archive

  • Science Buffs Features JILA’s Innovative Platform for Observing the Ultrafast and Ultrasmall | JILA-PFC
    Innovative Platform for Observing the Ultrafast and Ultrasmall Back to News Published 11 19 2015 Chris Mancuso Dan Hickstein Graduate student Chris Mancuso and senior research associate Dan Hickstein of the Kapteyn Murnane group recently spoke with Amanda Grennell a 5th year PhD candidate in Chemistry at the University of Colorado Boulder The researchers discussed the K M group s paper Strong field ionization with two color circularly polarized laser

    Original URL path: http://jila-pfc.colorado.edu/news/science-buffs-features-jila%E2%80%99s-innovative-platform-observing-ultrafast-and-ultrasmall (2016-04-29)
    Open archived version from archive

  • Debbie Jin & Jun Ye Highly Cited Researchers for 2015 | JILA-PFC
    form Search Advanced Other JILA Sites JILA Home Debbie Jin Jun Ye Highly Cited Researchers for 2015 Back to News Published 10 08 2015 Deborah Jin Jun Ye in the Cold Molecule Laboratory Credit Glenn Asakawa University of Colorado Deborah Jin and Jun Ye are Highly Cited Researchers for 2015 according to the Thomas Reuters website The website states Highly Cited Researchers 2015 represents some of world s most influential

    Original URL path: http://jila-pfc.colorado.edu/news/debbie-jin-jun-ye-highly-cited-researchers-2015 (2016-04-29)
    Open archived version from archive