We propose a scheme to realize a pseudospin- $1/2$ model of the ${}^{1}\mathrm{\ensuremath{\Sigma}}(v=0)$ bialkali polar molecules with the spin states corresponding to two sublevels of the first excited rotational level. We show that the effective dipole-dipole interaction between two spin- $1/2$ molecules couples the rotational and orbital angular momenta and is highly tunable via a microwave field. We also investigate the ground-state properties of a spin- $1/2$ molecular condensate. A variety of nontrivial quantum phases, including the doubly quantized vortex states, are discovered. Our scheme can also be used to create spin-1 model of polar molecules. Thus we show that the ultracold gases of bialkali polar molecules provide a unique platform for studying the spinor condensates of rotating molecules.We propose a scheme to realize a pseudospin-$1/2$ model of the ${}^{1}\mathrm{\ensuremath{\Sigma}}(v=0)$ bialkali polar molecules with the spin states corresponding to two sublevels of the first excited rotational level. We show that the effective dipole-dipole interaction between two spin-$1/2$ molecules couples the rotational and orbital angular momenta and is highly tunable via a microwave field. We also investigate the ground-state properties of a spin-$1/2$ molecular condensate. A variety of nontrivial quantum phases, including the doubly quantized vortex states, are discovered. Our scheme can also be used to create spin-1 model of polar molecules. Thus we show that the ultracold gases of bialkali polar molecules provide a unique platform for studying the spinor condensates of rotating molecules.

arXiv:1411.4258Physical Review ASep 25, 20154 citations

Towards two-dimensional quantum gases of strongly dipolar molecules

Aden Z. Lam, Niccolò Bigagli, Claire Warner +2 more

Bulletin of the American Physical SocietyMay 31, 20180 citations

Ultracold Li Cr : A New Pathway to Quantum Gases of Paramagnetic Polar Molecules

Stefano Finelli, A. Ciamei, Beatrice Restivo +8 more

Quantum gases of doubly polar molecules represent appealing frameworks for a variety of cross-disciplinary applications, encompassing quantum simulation and computation, controlled quantum chemistry, and precision measurements. Through a joint experimental and theoretical study, here we explore a novel class of ultracold paramagnetic polar molecules combining lithium alkali and chromium transition metal elements. Focusing on the specific bosonic isotopologue 6 Li 53 Cr , leveraging on the Fermi statistics of the parent atomic mixture and on suitable Feshbach resonances recently discovered, we produce up to 50 × 10 3 ultracold Li Cr molecules at peak phase-space densities exceeding 0.1, prepared within the least bound rotationless level of the Li Cr electronic ground state X 6 Σ + . By also developing new probing methods, we thoroughly characterize the molecular gas, demonstrating the paramagnetic nature of Li Cr dimers and the precise control of their quantum state. We investigate their stability against inelastic processes and identify a parameter region where pure Li Cr samples exhibit lifetimes exceeding 0.2 s. Parallel to this, we employ state-of-the-art quantum chemical calculations to accurately predict the properties of Li Cr ground and excited electronic states. This model, able to reproduce the experimental Li - Cr high-spin, scattering length, allows us to identify both efficient paths to coherently transfer weakly bound Li Cr dimers to their absolute ground state, and suitable transitions for their subsequent optical manipulation. Our studies establish Li - Cr as a prime candidate to realize ultracold gases of doubly polar molecules with significant electric (3.3 D) and magnetic ( 5 μ B ) dipole moments. Published by the American Physical Society 2024Quantum gases of doubly polar molecules represent appealing frameworks for a variety of cross-disciplinary applications, encompassing quantum simulation and computation, controlled quantum chemistry, and precision measurements. Through a joint experimental and theoretical study, here we explore a novel class of ultracold paramagnetic polar molecules combining lithium alkali and chromium transition metal elements. Focusing on the specific bosonic isotopologue 6 Li 53 Cr , leveraging on the Fermi statistics of the parent atomic mixture and on suitable Feshbach resonances recently discovered, we produce up to 50 × 10 3 ultracold Li Cr molecules at peak phase-space densities exceeding 0.1, prepared within the least bound rotationless level of the Li Cr electronic ground state X 6 Σ + . By also developing new probing methods, we thoroughly characterize the molecular gas, demonstrating the paramagnetic nature of Li Cr dimers and the precise control of their quantum state. We investigate their stability against inelastic processes and identify a parameter region where pure Li Cr samples exhibit lifetimes exceeding 0.2 s. Parallel to this, we employ state-of-the-art quantum chemical calculations to accurately predict the properties of Li Cr ground and excited electronic states. This model, able to reproduce the experimental Li - Cr high-spin, scattering length, allows us to identify both efficient paths to coherently transfer weakly bound Li Cr dimers to their absolute ground state, and suitable transitions for their subsequent optical manipulation. Our studies establish Li - Cr as a prime candidate to realize ultracold gases of doubly polar molecules with significant electric (3.3 D) and magnetic ( 5 μ B ) dipole moments. Published by the American Physical Society 2024

arXiv:2402.08337PRX QuantumJun 12, 202419 citations

Making a molecular gas in the quantum regime

Kang-Kuen Ni

Bulletin of the American Physical SocietyJun 7, 20170 citations

We propose a scheme to realize a pseudospin-

1/2

model of the ${}^{1}\mathrm{\ensuremath{\Sigma}}(v=0)$ bialkali polar molecules with the spin states corresponding to two sublevels of the first excited rotational level. We show that the effective dipole-dipole interaction between two spin-

1/2

molecules couples the rotational and orbital angular momenta and is highly tunable via a microwave field. We also investigate the ground-state properties of a spin-

1/2

molecular condensate. A variety of nontrivial quantum phases, including the doubly quantized vortex states, are discovered. Our scheme can also be used to create spin-1 model of polar molecules. Thus we show that the ultracold gases of bialkali polar molecules provide a unique platform for studying the spinor condensates of rotating molecules.