Absolute frequency measurement of 1S0 (F = 1/2) - 3P0 (F = 1/2)   transition of 171Yb atoms in a one-dimensional optical lattice at KRISS
  We measured the absolute frequency of the optical clock transition 1S0 (F = 1/2) - 3P0 (F = 1/2) of 171Yb atoms confined in a one-dimensional optical lattice and it was determined to be 518 295 836 590 863.5(8.1) Hz. The frequency was measured against Terrestrial Time (TT; the SI second on the geoid) by using an optical frequency comb of which the frequency was phase-locked to an H-maser as a flywheel oscillator traceable to TT. The magic wavelength was also measured as 394 798.48(79) GHz. The results are in good agreement with two previous measurements of other institutes within the specified uncertainty of this work. 
Chang Yong Park, Dai-Hyuk Yu, Won-Kyu Lee, Sang Eon Park, Eok Bong   Kim, Sun Kyung Lee, Jun Woo Cho, Tai Hyun Yoon, Jongchu...
physics.atom-ph