Letter abstract


Nature Physics 6, 265 - 270 (2010)
Published online: 21 February 2010 | doi:10.1038/nphys1533

Subject Categories: Atomic and molecular physics | Optical physics

An ultracold high-density sample of rovibronic ground-state molecules in an optical lattice

Johann G. Danzl1, Manfred J. Mark1, Elmar Haller1, Mattias Gustavsson1, Russell Hart1, Jesus Aldegunde2, Jeremy M. Hutson2 & Hanns-Christoph Nägerl1

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Control over all internal and external degrees of freedom of molecules at the level of single quantum states will enable a series of fundamental studies in physics and chemistry1, 2. In particular, samples of ground-state molecules at ultralow temperatures and high number densities will facilitate new quantum-gas studies3 and future applications in quantum information science4. However, high phase-space densities for molecular samples are not readily attainable because efficient cooling techniques such as laser cooling are lacking. Here we produce an ultracold and dense sample of molecules in a single hyperfine level of the rovibronic ground state with each molecule individually trapped in the motional ground state of an optical lattice well. Starting from a zero-temperature atomic Mott-insulator state5 with optimized double-site occupancy6, weakly bound dimer molecules are efficiently associated on a Feshbach resonance7 and subsequently transferred to the rovibronic ground state by a stimulated four-photon process with >50% efficiency. The molecules are trapped in the lattice and have a lifetime of 8s. Our results present a crucial step towards Bose–Einstein condensation of ground-state molecules and, when suitably generalized to polar heteronuclear molecules, the realization of dipolar quantum-gas phases in optical lattices8, 9, 10.

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  1. Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, Technikerstraße 25, A–6020 Innsbruck, Austria
  2. Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, UK

Correspondence to: Johann G. Danzl1 e-mail: johann.danzl@uibk.ac.at

Correspondence to: Hanns-Christoph Nägerl1 e-mail: christoph.naegerl@uibk.ac.at