Abstract
The saturated absorption spectrum of the hyperfineless S(0) quadrupole line in the (2-0) band of H2 is measured at λ=1189 nm, using the NICE-OHMS technique under cryogenic conditions (72 K). It is the first time that a Lamb dip of a molecular quadrupole transition has been recorded. At low (150-200 W) saturation powers a single narrow Lamb dip is observed, ruling out an underlying recoil doublet of 140 kHz. Studies of Doppler-detuned resonances show that the redshifted recoil component can be made visible for low pressures and powers, and prove that the narrow Lamb dip must be interpreted as the blue recoil component. A transition frequency of 252 016 361 164 (8) kHz is extracted, which is off by -2.6 (1.6) MHz from molecular quantum electrodynamical calculations therewith providing a challenge to theory.
| Original language | English |
|---|---|
| Article number | 073001 |
| Pages (from-to) | 1-6 |
| Number of pages | 6 |
| Journal | Physical review letters |
| Volume | 131 |
| Issue number | 7 |
| Early online date | 17 Aug 2023 |
| DOIs | |
| Publication status | Published - 18 Aug 2023 |
Bibliographical note
Funding Information:Financial support from the Netherlands Organisation for Scientific Research (NWO), via the Program “The Mysterious Size of the Proton” is gratefully acknowledged. We thank several members of the Quantum Metrology & Laser Applications group at VU Amsterdam (Edcel Salumbides, Max Beyer, Kjeld Eikema, Jeroen Koelemeij, Yuri van der Werf, Hendrick Bethlem) for helpful discussions.
Publisher Copyright:
© 2023 American Physical Society.
Funding
Financial support from the Netherlands Organisation for Scientific Research (NWO), via the Program “The Mysterious Size of the Proton” is gratefully acknowledged. We thank several members of the Quantum Metrology & Laser Applications group at VU Amsterdam (Edcel Salumbides, Max Beyer, Kjeld Eikema, Jeroen Koelemeij, Yuri van der Werf, Hendrick Bethlem) for helpful discussions.