BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-3801 DTSTART:20151105T160000Z DTEND:20151105T170000Z DTSTAMP:20260311T032959Z LAST-MODIFIED:20151030T124358Z LOCATION:Chamberlin 5310 SUMMARY:Detecting frequency fluctuations in mesoscopic oscillators\, R . G. Herb Condensed Matter Seminar\, Yaxing Zhang\, Michigan State Uni versity DESCRIPTION:Mesoscopic oscillators\, such as nanomechanical resonators or optomechanical systems\, usually experience comparatively large fl uctuations due to their small size. An important type of fluctuations is frequency fluctuations\, that is\, the oscillator eigenfrequency is subject to a random perturbation in time. For nanomechanical resonato rs\, frequency fluctuations can come from tension and mass fluctuation s\, fluctuating charges in the substrate\, or dispersive inter-mode co upling\; for electromagnetic cavity modes\, they can come from fluctua tions of dielectric constant. Frequency fluctuations lead to the broad ening of oscillator linewidth. However\, this broadening is partly mas ked by the broadening due to oscillator decay\, making the identificat ion of frequency noise difficult. In this talk\, I will show that the interplay of a resonant driving and frequency noise can lead to specif ic features in the oscillator power spectrum that allow sensitive dete ction and quantitive characterization of frequency noise. I will start with a generic analysis of a harmonic oscillator with frequency noise \, corroborated by measurements on a carbon nanotube resonantor [1]. T hen I will discuss a particular type of frequency noise that comes fro m dispersive inter-mode coupling based on microscopic descriptions [2] .
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\n[1] Zhang\, Y.\, Moser\, J.\, Güttinger\, J.\, Bachto ld\, A. & Dykman\, M. I. Interplay of driving and frequency noise in t he spectra of vibrational systems. Phys. Rev. Lett. 113\, 255502 (2014 ).
\n[2] Zhang\, Y. & Dykman\, M. I. Spectral effects of dispersi ve mode coupling in driven mesoscopic systems. Phys. Rev. B 92\, 16541 9 (2015).
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\n URL:https://www.physics.wisc.edu/events/?id=3801 END:VEVENT END:VCALENDAR