NCTS (South)


DATE2013-01-10

TIME14:10

PLACER49223, Second Physics Building , NCKU

FIELDOther

SPEAKER 藍劭宇 - UC Berkeley, USA

TITLEAtom Interferometry Experiments for Precision Measurement of Fundamental Physics

ABSTRACTLight-pulse atom interferometers have already been used as quantum inertial sensors and to test the fundamental physics with high precision and accuracy. In this talk, I will first give an overview of light-pulse atom interferometers and demonstrate our recent developments of high sensitive interferometers using large-momentum transfer beam splitters, common mode rejection, and Coriolis force compensation. Combining with an optical frequency comb, I will present the first clock referenced the mass of a single particle only. The rest mass of a particle defines its Compton frequency, mc2/ through relativity and quantum mechanics, and thereby sets a fundamental timescale. However, the Compton frequency of a single, non-interacting particle is too high to be harnessed as a clock (about 3×1025 Hz for a cesium atom) and does not directly give rise to observable effects. The relative phase accumulated between matter-waves travelling along different paths provides us with an indirect way to access the Compton frequency. Our clock stabilizes a radio-frequency signal to a certain fraction of the Cs Compton frequency. I will also give you an update of our recent progress on a new determination of fine structure constant reaching sub-ppb level using large momentum transfer atom interferometers.