TY - JOUR
T1 - Improved Measurement of the Hydrogen $1S--2S$ Transition Frequency
AU - Parthey, Christian G.
AU - Matveev, Arthur
AU - Alnis, Janis
AU - Bernhardt, Birgitta
AU - Beyer, Axel
AU - Holzwarth, Ronald
AU - Maistrou, Aliaksei
AU - Pohl, Randolf
AU - Predehl, Katharina
AU - Udem, Thomas
AU - Wilken, Tobias
AU - Kolachevsky, Nikolai
AU - Abgrall, Michel
AU - Rovera, Daniele
AU - Salomon, Christophe
AU - Laurent, Philippe
AU - Hänsch, Theodor W.
PY - 2011/11/1
Y1 - 2011/11/1
N2 - We have measured the 1S–2S transition frequency in atomic hydrogen via two-photon spectroscopy on a 5.8 K atomic beam. We obtain f1S–2S=2 466 061 413 187 035 (10) Hz for the hyperfine centroid, in agreement with, but 3.3 times better than the previous result [M. Fischer et al., Phys. Rev. Lett. 92, 230802 (2004)]. The improvement to a fractional frequency uncertainty of 4.2×10−15 arises mainly from an improved stability of the spectroscopy laser, and a better determination of the main systematic uncertainties, namely, the second order Doppler and ac and dc Stark shifts. The probe laser frequency was phase coherently linked to the mobile cesium fountain clock FOM via a frequency comb.
AB - We have measured the 1S–2S transition frequency in atomic hydrogen via two-photon spectroscopy on a 5.8 K atomic beam. We obtain f1S–2S=2 466 061 413 187 035 (10) Hz for the hyperfine centroid, in agreement with, but 3.3 times better than the previous result [M. Fischer et al., Phys. Rev. Lett. 92, 230802 (2004)]. The improvement to a fractional frequency uncertainty of 4.2×10−15 arises mainly from an improved stability of the spectroscopy laser, and a better determination of the main systematic uncertainties, namely, the second order Doppler and ac and dc Stark shifts. The probe laser frequency was phase coherently linked to the mobile cesium fountain clock FOM via a frequency comb.
U2 - 10.1103/PhysRevLett.107.203001
DO - 10.1103/PhysRevLett.107.203001
M3 - Article
VL - 107
SP - 203001
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
ER -