Quantum Optics Laboratory

After remarkable progress with laser cooled atoms in diverse fields from atomic clocks to quantum information processing, physicists are exploring a next frontier: cold molecules. While these systems could lead to profound developments, for example probing the predictions of fundamental theories and realizing controlled chemical reactions, the vibrational and rotational degrees of freedom in molecules pose a formidable challenge for preparation and manipulation of their quantum mechanical states. The complicated molecular level structures render the highly successful methods in atomic physics inapplicable to most molecules. By driving stimulated Raman transitions with a continuous-wave laser, we demonstrate a general protocol for preparation, coherent manipulation, and nondestructive detection of quantum states in single molecular ions [1]. We also drive rotational transitions in the terahertz range with a frequency comb [2-4], enabling transfer of population between rotational levels and precise determination of the transition frequency. Our work provides a versatile toolbox for the study of a broad range of molecular ions, adding to the capabilities developed in atomic physics over the last several decades. This opens the path to applications in fundamental physics, metrology, and quantum control.

[1] C. W. Chou, C. Kurz, D. B. Hume, P. N. Plessow, D. R. Leibrandt, and D. Leibfried, Nature 545, 203 (2017).

[2] D. Hayes, D. N. Matsukevich, P. Maunz, D. Hucul, Q. Quraishi, S. Olmschenk, W. Campbell, J. Mizrahi, C. Senko, and C. Monroe, Phys. Rev. Lett. 104, 140501 (2010).

[3] S. Ding and D. N. Matsukevich, New J. Phys. 14, 023028 (2012).

[4] D. Leibfried, New J. Phys. 14, 023029 (2012).