Testing quantum electrodynamic effects in molecules

Abstract

Recently, we reported a systematic test of quantum electrodynamic (QED) effects in the progression of rotational quantum states in the X¹Î£⁺_g, v = 0 vibronic ground state of molecular hydrogen. High precision Doppler-free spectroscopy of the EF¹Î£⁺_g − X¹Î£⁺_g(0,0) band was performed with 0.005 cm^−1 accuracy on rotationally-hot H₂. The extracted QED and relativistic contributions to rotational level energies are in perfect agreement with recent calculations of QED and leading-order relativistic effects for the H₂ ground state. We also present a new determination of the fundamental vibrational splitting in H₂ ground state.