Evaporative cooling of the dipolar radical OH

Abstract

Atomic physics was revolutionized by the development of forced evaporative cooling: it led directly to the observation of Bose-Einstein condensation, quantum-degenerate Fermi gases, and ultracold optical lattice simulations of condensed matter phenomena. More recently, great progress has been made in the production of cold molecular gases, whose permanent electric dipole moment is expected to generate rich, novel, and controllable phases, dynamics, and chemistry in these ultracold systems. However, while many strides have been made in both direct cooling and cold-association techniques, evaporative cooling has not yet been achieved due to unfavorable elastic-to-inelastic ratios and impractically slow thermalization rates in the available trapped species. We now report the observation of microwave-forced evaporative cooling of hydroxyl (OH) molecules loaded from a Stark-decelerated beam into an extremely high-gradient magnetic quadrupole trap. We demonstrate cooling by at least an order of magnitude in temperature and three orders in phase-space density, limited only by the low-temperature sensitivity of our spectroscopic thermometry technique. With evaporative cooling and sufficiently large initial populations, much colder temperatures are possible, and even a quantum-degenerate gas of this dipolar radical -- or anything else it can sympathetically cool -- may now be in reach.

6 pages, 4 figures

References in corpus (9)

• A High Phase-Space-Density Gas of Polar Molecules
• Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential
• Cold Atoms and Molecules in Self-Assembled Dipolar Lattices
• Low-energy molecular collisions in a permanent magnetic trap
• Ultracold Rb-OH collisions and prospects for sympathetic cooling
• OH hyperfine ground state: from precision measurement to molecular qubits
• Large Effects of Electric Fields on Atom-Molecule Collisions at Millikelvin Temperatures
• Mechanism of Collisional Spin Relaxation in Triplet-Sigma Molecules
• Efficient method for quantum calculations of molecule - molecule scattering properties in a magnetic field

Cited by in corpus (90)

• Cold molecules: Progress in Quantum Engineering of Chemistry and Quantum Matter
• Magneto-optical trapping of a diatomic molecule
• Coherent coupling of molecular resonators with a micro-cavity mode
• Dipolar physics: A review of experiments with magnetic quantum gases
• Magneto-optical trapping of diatomic molecules
• Quantum control of molecular rotation
• Laser cooling and slowing of CaF molecules
• Manipulation of Molecules with Electromagnetic Fields
• New frontiers with quantum gases of polar molecules
• Sub-millikelvin dipolar molecules in a radio-frequency magneto-optical trap
• Polyatomic Molecules as Quantum Sensors for Fundamental Physics
• Quantum degenerate mixtures of strontium and rubidium atoms
• Collisional Cooling of Ultracold Molecules
• Observation of Collisions between Two Ultracold Ground-State CaF Molecules
• Rotational state microwave mixing for laser cooling of complex diatomic molecules
• Laser cooling of molecules
• Laser slowing of CaF molecules to near the capture velocity of a molecular MOT
• Strongly interacting ultracold polar molecules
• An intense, cold, velocity-controlled molecular beam by frequency-chirped laser slowing
• Realizing unconventional quantum magnetism with symmetric top molecules
• The {\it ab initio} calculation of spectra of open shell diatomic molecules
• Collisions between cold molecules in a superconducting magnetic trap
• Improved magneto-optical trapping of a diatomic molecule
• Controlling a quantum gas of polar molecules in an optical lattice
• Shielding ${}^2\Sigma$ ultracold dipolar molecular collisions with electric fields
• Magnetic Trapping of Molecules via Optical Loading and Magnetic Slowing
• Magnetic Trapping of Cold Methyl Radicals
• Spectroscopic characterization of aluminum monofluoride with relevance to laser cooling and trapping
• Buffer-gas cooling, high-resolution spectroscopy and optical cycling of barium monofluoride molecules
• Static trapping of polar molecules in a traveling wave decelerator
• Adimensional theory of shielding in ultracold collisions of dipolar rotors
• Trapping of molecular Oxygen together with Lithium atoms
• Tuning ultracold collisions of excited rotational dipolar molecules
• Rotational friction and diffusion of quantum rotors
• Time-dependent wave packet dynamics calculations of cross sections for ultracold scattering of molecules
• Two-Photon Pathway to Ultracold Ground State Molecules of ${}^{23}$Na${}^{40}$K
• Optical trapping of ultracold dysprosium atoms: transition probabilities, dynamic dipole polarizabilities and van der Waals $C_6$ coefficients
• Prospects for a Narrow Line MOT in YO
• Quantum state resolved molecular dipolar collisions over four decades of energy
• Diatomic molecules of alkali-metal and alkaline-earth-metal atoms: interaction potentials, dipole moments, and polarizabilities
• Nonadiabatic Effects in Ultracold Molecules via Anomalous Linear and Quadratic Zeeman Shifts
• Principles and design of a Zeeman-Sisyphus decelerator for molecular beams
• Controlling Spin-flips of Molecules in an Electromagnetic Trap
• Spectroscopy on the $A^1\Pi \leftarrow X^1{\Sigma }^{+}$ Transition of Buffer-Gas Cooled AlCl
• Hyperfine structure of the hydroxyl free radical (OH) in electric and magnetic fields
• Ultracold nonreactive molecules in an optical lattice: connecting chemistry to many-body physics
• Quantum defect model of a reactive collision at finite temperature
• Deceleration and trapping of ammonia molecules in a traveling wave decelerator
• Molecular Collisions: from Near-cold to Ultra-cold
• Optimized cell geometry for buffer-gas-cooled molecular-beam sources
• Ultracold molecular collisions in combined electric and magnetic fields
• Multistage Zeeman deceleration of NH $X{}^3{\Sigma }^{-}$ radicals
• Model for the hyperfine structure of electronically-excited $\mathrm{KCs}$ molecules
• One dimensional magneto-optical compression of a cold CaF molecular beam
• Microscopic derivation of multi-channel Hubbard models for ultracold nonreactive molecules in an optical lattice
• Ultracold hydrogen atoms: a versatile coolant to produce ultracold molecules
• Low-temperature chemistry using the R-matrix method
• Simulation of Cryogenic Buffer Gas Beams
• Lattice model parameters for ultracold nonreactive molecules: chaotic scattering and its limitations
• Efficient polarization of high-angular-momentum systems
• Dipolar Radicals in Crossed Electric and Magnetic Fields
• Laser cooling of rotation and vibration by optical pumping
• Speeding Up Particle Slowing using Shortcuts to Adiabaticity
• Low temperature scattering with the R-matrix method: argon-argon scattering
• Fine Structure of Open Shell Diatomic Molecules in Combined Electric and Magnetic Fields
• Ground-state OH molecule in combined electric and magnetic fields: Analytic solution of the effective Hamiltonian
• Dynamics of ultracold dipolar particles in a confined geometry and tilted fields
• The Multi-component Correlated Basis Function Method and its Application to Multilayered Dipolar Bose Gases
• Production of translationally cold barium monohalide ions
• Associative detachment of rubidium hydroxide
• Superfluidity of a dipolar Fermi gas in 2D optical lattices bilayer
• Measuring and manipulating the temperature of cold molecules trapped on a chip
• Elastic and inelastic collisions of ${}^2\Sigma$ molecules in a magnetic field
• Measurements of trap dynamics of cold OH molecules using resonance enhanced multiphoton ionization
• The Dynamics of an Electric Dipole Moment in a Stochastic Electric Field
• Multichannel Quantum Defect Theory for cold molecular collisions with a strongly anisotropic potential energy surface
• Measurement of Doppler effects in cryogenic buffer-gas cell
• Orbital phases of fermions in an asymmetric optical ladder
• Vibrational quenching of the electronic ground state in ThO in cold collisions with ${}^3$He
• A proposal for sympathetically cooling neutral molecules using cold ions
• Reactions between cold methyl halide molecules and alkali-metal atoms
• Spin Waves and Dielectric Softening of Polar Molecule Condensates
• Effects of Conical Intersections on Hyperfine Quenching of Hydroxyl OH in collision with an ultracold Sr atom
• Can Nitric Oxide be Evaporatively Cooled in its Ground State?
• Analytical study of level crossings in the Stark-Zeeman spectrum of ground state OH
• Two-state Bogoliubov theory of a molecular Bose gas
• Spin squeezing an ultracold molecule
• Analysis of two and three dipolar bosons in a spherical harmonic trap
• Simultaneous Zeeman deceleration of polyatomic free radical with lithium atoms
• Low-temperature scattering with the R-matrix method: from nuclear scattering to atom-atom scattering and beyond