Evaporation of microwave-shielded polar molecules to quantum degeneracy

Abstract

Ultracold polar molecules offer strong electric dipole moments and rich internal structure, which makes them ideal building blocks to explore exotic quantum matter, implement novel quantum information schemes, or test fundamental symmetries of nature. Realizing their full potential requires cooling interacting molecular gases deeply into the quantum degenerate regime. However, the complexity of molecules which makes their collisions intrinsically unstable at the short range, even for nonreactive molecules, has so far prevented the cooling to quantum degeneracy in three dimensions. Here, we demonstrate evaporative cooling of a three-dimensional gas of fermionic sodium-potassium molecules to well below the Fermi temperature using microwave shielding. The molecules are protected from reaching short range with a repulsive barrier engineered by coupling rotational states with a blue-detuned circularly polarized microwave. The microwave dressing induces strong tunable dipolar interactions between the molecules, leading to high elastic collision rates that can exceed the inelastic ones by at least a factor of 460. This large elastic-to-inelastic collision ratio allows us to cool the molecular gas down to 21 nanokelvin, corresponding to 0.36 times the Fermi temperature. Such unprecedentedly cold and dense samples of polar molecules open the path to the exploration of novel many-body phenomena, such as the long-sought topological p-wave superfluid states of ultracold matter.

11 pages, 7 figures

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• Efficient conversion of closed-channel dominated Feshbach molecules of ${}^{23}$Na${}^{40}$K to their absolute ground state
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Cited by in corpus (94)

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• Dipolar quantum solids emerging in a Hubbard quantum simulator
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• Collisionally Stable Gas of Bosonic Dipolar Ground State Molecules
• Tunable itinerant spin dynamics with polar molecules
• Ultracold Gas of Dipolar NaCs Ground State Molecules
• Ultracold Sticky Collisions: Theoretical and Experimental Status
• Heating a dipolar quantum fluid into a solid
• Microwave shielding of bosonic NaRb molecules
• A Feshbach resonance in collisions between ultracold ground state molecules
• Field-linked resonances of polar molecules
• Blue-Detuned Magneto-Optical Trap of Molecules
• Quantum state resolved molecular dipolar collisions over four decades of energy
• Ultracold field-linked tetratomic molecules
• Diatomic molecules of alkali-metal and alkaline-earth-metal atoms: interaction potentials, dipole moments, and polarizabilities
• Effective potential and superfluidity of microwave-dressed polar molecules
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• Observation of generalized t-J spin dynamics with tunable dipolar interactions
• Pinpointing Feshbach Resonances and Testing Efimov Universalities in ${}^{39}$K
• High density loading and collisional loss of laser cooled molecules in an optical trap
• Raman Sideband Cooling of Molecules in an Optical Tweezer Array
• Towards improved loading, cooling, and trapping of molecules in magneto-optical traps
• Magnetism in the two-dimensional dipolar XY model
• Double Microwave Shielding
• Electro-association of ultracold dipolar molecules into tetramer field-linked states
• Recent progress on quantum simulations of non-standard Bose-Hubbard models
• Observation of photoassociation resonances in ultracold atom-molecule collisions
• Shielding collisions of ultracold CaF molecules with static electric fields
• SU(N) magnetism with ultracold molecules
• Preparation of a quantum degenerate mixture of ${}^{23}$Na${}^{40}$K molecules and ${}^{40}$K atoms
• Blackbody thermalization and vibrational lifetimes of trapped polyatomic molecules
• Spin exchange-enabled quantum simulator for large-scale non-Abelian gauge theories
• Three-Body Recombination of Ultracold Microwave-Shielded Polar Molecules
• Spin rotons and supersolids in binary antidipolar condensates
• Two-photon optical shielding of collisions between ultracold polar molecules
• Efficient Pathway to NaCs Ground State Molecules
• Enhanced quantum state transfer via feedforward cancellation of optical phase noise
• Controlling collisional loss and scattering lengths of ultracold dipolar molecules with static electric fields
• Rotational-state dependence of interactions between polar molecules
• Laser cooling of a fermionic molecule
• Thermoviscous Hydrodynamics in Non-Degenerate Dipolar Bose Gases
• Symmetry breaking in sticky collisions between ultracold molecules
• Fast loading of a cold mixture of Sodium and Potassium atoms from compact and versatile cold atomic beam sources
• Chemical reactions of ultracold alkaline-earth-metal diatomic molecules
• Thermal Conductivity of an Ultracold Paramagnetic Bose Gas
• Collisions of Spin-polarized YO Molecules for Single Partial Waves
• Anisotropic acoustics in dipolar Fermi gases
• Long-lived fermionic Feshbach molecules with tunable $p$-wave interactions
• A planar cloverleaf antenna for the creation of circularly polarized microwave fields
• Coherence of Symmetry-Protected Rotational Qubits in Cold Polyatomic Molecules
• SU($N$) symmetry with ultracold alkali dimers: weak dependence of scattering properties on hyperfine state
• Calibrating the absorption imaging of cold atoms under high magnetic fields
• Scheme for Deterministic Loading of Laser-Cooled Molecules into Optical Tweezers
• Quantum Monte Carlo and perturbative study of two-dimensional Bose-Fermi mixtures
• Nonequilibrium quench dynamics of Bose-Einstein condensates of microwave-shielded polar molecules
• Intercombination line photoassociation spectroscopy of ${}^{87}$Rb${}^{170}$Yb
• Resonances in non-universal dipolar collisions
• Spin Squeezing with Itinerant Dipoles: A Case for Shallow Lattices
• Boson-fermion pairing and condensation in two-dimensional Bose-Fermi mixtures
• Ultracold Interactions between Ions and Polar Molecules
• Emergent Mott-insulators at non-integer fillings and devil's staircase induced by attractive interaction in many-body polarons
• Effective potential and scattering length of shielding polar molecules
• Dissipative Superfluidity in a Molecular Bose-Einstein Condensate
• Probing rotational decoherence with a trapped-ion planar rotor
• Synthetic Mutual Gauge Field in Microwave-Shielded Polar Molecular Gases
• Dressed-State Spectroscopy and Magic Trapping of Microwave-Shielded NaCs Molecules
• Genetics-based deperturbation analysis for the spin-orbit coupled ${\mathrm{A}}^1{\Sigma }^{+}$ and ${\mathrm{b}}^3{\Pi }_{0^{+}}$ states of LiRb
• Fate of thermalization of ultracold fermions with two-body dissipation
• Atom-Molecule Superradiance and Entanglement with Cavity-Mediated Three-Body Interactions
• Macroscopic Particle Transport in Dissipative Long-Range Bosonic Systems
• Mechanical stability of resonant Bose-Fermi mixtures
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• Ground-state selection via many-body superradiant decay
• Solving the SU($N$) Orbital Hatsugai-Kohmoto Model
• Ultracold coherent control of molecular collisions at a Förster resonance
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• Multi-state detection and spatial addressing in a microscope for ultracold molecules
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• Competition of light- and phonon-dressing in microwave-dressed Bose polarons
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