Laser cooling of a diatomic molecule

By E. Shuman, J. Barry, D. DeMille. Nature, 2010

685 citations recorded by the source corpus.

It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a wide array of fields. Laser cooling has not yet been extended to molecules because of their complex internal structure. However, this complexity makes molecules potentially useful for a wide range of applications. For example, heteronuclear molecules possess permanent electric dipole moments that lead to long-range, tunable, anisotropic dipole–dipole interactions. The combination of the dipole–dipole interaction and the precise control over molecular degrees of freedom possible at ultracold temperatures makes ultracold molecules attractive candidates for use in quantum simulations of condensed-matter systems and in quantum computation. Also, ultracold molecules could provide unique opportunities for studying chemical dynamics and for tests of fundamental symmetries. Here we experimentally demonstrate laser cooling of the polar molecule strontium monofluoride (SrF). Using an optical cycling scheme requiring only three lasers, we have observed both Sisyphus and Doppler cooling forces that reduce the transverse temperature of a SrF molecular beam substantially, to a few millikelvin or less. At present, the only technique for producing ultracold molecules is to bind together ultracold alkali atoms through Feshbach resonance or photoassociation. However, proposed applications for ultracold molecules require a variety of molecular energy-level structures (for example unpaired electronic spin, Omega doublets and so on). Our method provides an alternative route to ultracold molecules. In particular, it bridges the gap between ultracold (submillikelvin) temperatures and the ∼1-K temperatures attainable with directly cooled molecules (for example with cryogenic buffer-gas cooling or decelerated supersonic beams). Ultimately, our technique should allow the production of large samples of molecules at ultracold temperatures for species that are chemically distinct from bialkalis.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/f0334b23f0a9c34a867f116b9abc8cd079d0657d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Models of Wave-function Collapse, Underlying Theories, and Experimental Tests (2012, background): “This especially includes the collisional buffer gas cooling (Maxwell et al., 2005) as well as optical cooling techniques (Shuman et al., 2010).”
Molecules cooled below the Doppler limit (2017, methodology): “Major increases in density are likely to come from more efficient slowing methods [30] along with transverse cooling [2] prior to slowing.”
Measuring the electric dipole moment of the electron in BaF (2018, methodology): “ accompanied by a signicant decrease in the counting rate N_ . However, recent advances in decelerating molecular beams [39, 40, 41, 42] combined with spectacular progress in molecular laser cooling [43] and the demonstration of intense cryogenic molecular beam sources [44] have opened a route to ci”
Quantum control of molecular rotation (2018, background): “Strontium monofluoride (Shuman et al., 2009; Shuman, Barry, and DeMille, 2010) and yttrium (II) oxide (Hummon et al., 2013) have thus been laser cooled to temperatures of a few millikelvin.”
Robust Encoding of a Qubit in a Molecule (2019, background): “Nevertheless, significant steps toward the realization of molecular codes may be feasible during the NISQ era [31] as the technology for trapping and controlling molecules [33–38] continues to advance.”