|Budget Amount *help
¥199,550,000 (Direct Cost: ¥153,500,000、Indirect Cost: ¥46,050,000)
Fiscal Year 2013: ¥35,490,000 (Direct Cost: ¥27,300,000、Indirect Cost: ¥8,190,000)
Fiscal Year 2012: ¥50,700,000 (Direct Cost: ¥39,000,000、Indirect Cost: ¥11,700,000)
Fiscal Year 2011: ¥50,700,000 (Direct Cost: ¥39,000,000、Indirect Cost: ¥11,700,000)
Fiscal Year 2010: ¥40,560,000 (Direct Cost: ¥31,200,000、Indirect Cost: ¥9,360,000)
Fiscal Year 2009: ¥22,100,000 (Direct Cost: ¥17,000,000、Indirect Cost: ¥5,100,000)
We aim at search for a temporal variation of the fine structure constant by frequency-ratio measurement between the single-ion optical clocks, of which references are different transitions in Yb+ and Ba+. Detection of a temporal variation will lead to a new theory which reveals the origin of the dark energy.
We succeeded in single-ion spectroscopy of the 2S1/2-2D5/2 transition in 174Yb+, and then, 2S1/2-2D3/2 in 171Yb+ of a potential of better uncertainty, and the success enables us to realize the optical clocks of different transitions. We realized optical frequency-ratio measurement, and are developing a system of long-term continuous operation with a Yb:KYW laser. We achieved almost all the techniques required, including a clock laser with a 1-Hz linewidth, a surface trap of better detection efficiency of the fluorescence, and preparations for other clock transitions. We will measure uncertainties of the clocks, and start searching a temporal variation in the near future.