Molecular Optical Lattice Clock

Chih-Hsi Lee, Stanimir Kondov, Christian Liedl +2 more

Mateusz Borkowski

Tanya Zelevinsky

Abstract : We have established the strontium molecular clock as the leading ultracold-molecule precision measurement platform. We can fully control the molecules internal and external quantum states, as in state-of-the-art atomic lattice clocks. Using the quantized molecular spectra in an optical lattice, we devised a new lattice thermometry method that is advantageous for many lattice experiments, including clocks and manybody physics studies. The full quantum control allowed us to observe deeply subradiant molecular states, and coherently control them. We measured lifetimes enhanced by up to 300 times. Ultranarrow transitions to these states permitted a rigorous study of asymptotic physics at the atom-molecule threshold. We proved that subradiant states can decay to the ground state via higher-order electromagnetic transitions, with a rate that grows as the square of the bond length, and are quenched by predissociation at a rate proportional to the vibrational level spacing. We introduced a precise technique for measuring molecular binding energies via photofragmentation; controlled forbidden optical transition strengths with weak magnetic fields by five orders of magnitude; and explained anomalously large magnetic susceptibilities of the asymptotic molecules. The unprecedented precision, coupled with advanced ab initio theory, paves the way to exciting new directions for the molecular clock.

Masao Takamoto, Hidetoshi Katori

Kon H. Leung, Brandon Iritani, Emily Tiberi +4 more

Neutral quantum absorbers in optical lattices have emerged as a leading platform for achieving clocks with exquisite spectroscopic resolution.However, the studies of these clocks and their systematic shifts have so far been limited to atoms.Here, we extend this architecture to an ensemble of diatomic molecules and experimentally realize an accurate lattice clock based on pure molecular vibration.We evaluate the leading systematics, including the characterization of nonlinear trap-induced light shifts, achieving a total systematic uncertainty of 4.6 × 10 -14 .The absolute frequency of the vibrational splitting is measured to be 31 825 183 207 592.8(5.1)Hz, enabling the dissociation energy of our molecule to be determined with record accuracy.Our results represent an important milestone in molecular spectroscopy and THzfrequency standards, and may be generalized to other neutral molecular species with applications for fundamental physics, including tests of molecular quantum electrodynamics and the search for new interactions.

S. S. Kondov, C.-H. Lee, K. H. Leung +4 more