TY - JOUR
T1 - Ultracold metastable helium: Ramsey fringes and atom interferometry
AU - Vassen, W.
AU - Notermans, R.P.M.J.W.
AU - Rengelink, R.J.
AU - van der Beek, R.F.H.J.
PY - 2016/11/26
Y1 - 2016/11/26
N2 - We report on interference studies in the internal and external degrees of freedom of metastable triplet helium atoms trapped near quantum degeneracy in a 1.5μm optical dipole trap. Applying a single π/ 2 rf pulse we demonstrate that 50% of the atoms initially in the m= + 1 state can be transferred to the magnetic field insensitive m= 0 state. Two π/ 2 pulses with varying time delay allow a Ramsey-type measurement of the Zeeman shift for a high precision measurement of the 23S1–21S0 transition frequency. We show that this method also allows strong suppression of mean-field effects on the measurement of the Zeeman shift, which is necessary to reach the accuracy goal of 0.1 kHz on the absolute transition frequencies. Theoretically the feasibility of using metastable triplet helium atoms in the m= 0 state for atom interferometry is studied demonstrating favorable conditions, compared to the alkali atoms that are used traditionally, for a non-QED determination of the fine structure constant.
AB - We report on interference studies in the internal and external degrees of freedom of metastable triplet helium atoms trapped near quantum degeneracy in a 1.5μm optical dipole trap. Applying a single π/ 2 rf pulse we demonstrate that 50% of the atoms initially in the m= + 1 state can be transferred to the magnetic field insensitive m= 0 state. Two π/ 2 pulses with varying time delay allow a Ramsey-type measurement of the Zeeman shift for a high precision measurement of the 23S1–21S0 transition frequency. We show that this method also allows strong suppression of mean-field effects on the measurement of the Zeeman shift, which is necessary to reach the accuracy goal of 0.1 kHz on the absolute transition frequencies. Theoretically the feasibility of using metastable triplet helium atoms in the m= 0 state for atom interferometry is studied demonstrating favorable conditions, compared to the alkali atoms that are used traditionally, for a non-QED determination of the fine structure constant.
U2 - 10.1007/s00340-016-6563-0
DO - 10.1007/s00340-016-6563-0
M3 - Article
VL - 2016
JO - Applied Physics B. Lasers and Optics
JF - Applied Physics B. Lasers and Optics
SN - 0946-2171
IS - 122
M1 - 289
ER -