BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-4456 DTSTART:20170504T150000Z DURATION:PT1H0M0S DTSTAMP:20260419T043727Z LAST-MODIFIED:20170426T113547Z LOCATION:5310 Chamberlin SUMMARY:Coherent defects in diamond\, R. G. Herb Condensed Matter Semi nar\, Nathalie de Leon\, Princeton DESCRIPTION:Engineering coherent systems is a central goal of quantum science and quantum information processing. Point defects in diamond k nown as color centers are a promising physical platform. As atom-like systems\, they can exhibit excellent spin coherence and can be manipul ated with light. As solid-state defects\, they can be produced at high densities and incorporated into scalable devices. Diamond is a unique ly excellent host: it has a large band gap\, can be synthesized with s ub-ppb impurity concentrations\, and can be isotopically purified to e liminate magnetic noise from nuclear spins. Specifically\, the nitroge n vacancy (NV) center has been used to has been used to demonstrate ba sic building blocks of quantum networks and quantum computers\, and ha s been demonstrated to be a highly sensitive\, non-invasive magnetic p robe capable of resolving the magnetic field of a single electron spin with nanometer spatial resolution. However\, realizing the full poten tial of these systems requires the ability to both understand and mani pulate diamond as a material. I will present two recent results that d emonstrate how carefully tailoring the diamond host can dramatically i mprove the performance of color centers for various applications.
\nFirst\, currently-known color centers either exhibit long spin coher ence times or efficient\, coherent optical transitions\, but not both. We have developed new methods to control the diamond Fermi level in o rder to stabilize a new color center\, the neutral charge state of the silicon vacancy (SiV) center\, which exhibits both the excellent opti cal properties of the negatively charged SiV center and the long spin coherence times of the NV center\, making it a promising candidate for applications as a single atom quantum memory for long distance quantu m communication.
\nSecond\, color centers placed close to the diam ond surface can have strong interactions with molecules and materials external to the diamond. However\, uncontrolled surface termination an d contamination can degrade the color center properties and give rise to noise that obscures the signal of interest. I will describe our rec ent efforts to stabilize shallow NV centers within 5 nm of the surface using new surface processing and termination techniques. These highly coherent\, shallow NV centers will provide a platform for sensing and imaging down to the scale of single atoms.
\n URL:https://www.physics.wisc.edu/events/?id=4456 END:VEVENT END:VCALENDAR