Ultracold LiCr: A New Pathway to Quantum Gases of Paramagnetic Polar Molecules
Year: 2024
Authors: Finelli S., Ciamei A., Restivo B., Schemmer M., Cosco A., Inguscio M., Trenkwalder A., Zaremba-Kopczyk K., Gronowski M., Tomza M., Zaccanti M.
Autors Affiliation: Univ Firenze, Dipartimento Fis & Astron, I-50019 Sesto Fiorentino, Italy; Ist Nazl Ott Consiglio Nazl Ric CNR INO, I-50019 Sesto Fiorentino, Italy; Univ Firenze, European Lab Nonlinear Spect LENS, I-50019 Sesto Fiorentino, Italy; Campus Biomed Univ Rome, Dept Engn, I-00128 Rome, Italy; Univ Warsaw, Fac Phys, Pasteura 5, PL-02 093 Warsaw, Poland.
Abstract: 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 (LiCr)-Li-6-Cr-53, leveraging on the Fermi statistics of the parent atomic mixture and on suitable Feshbach resonances recently discovered, we produce up to 50 x 10(3) ultracold LiCr molecules at peak phase-space densities exceeding 0.1, prepared within the least bound rotationless level of the LiCr electronic sextet ground state X (6)Sigma(+). By also developing new probing methods, we thoroughly characterize the molecular gas, demonstrating the paramagnetic nature of LiCr dimers and the precise control of their quantum state. We investigate their stability against inelastic processes and identify a parameter region where pure LiCr 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 LiCr ground and excited electronic states. This ab initio model, able to reproduce the experimental Li-Cr high-spin, octet scattering length, allows us to identify both efficient paths to coherently transfer weakly bound LiCr 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 mu(B)) dipole moments.
Journal/Review: PRX QUANTUM
Volume: 5 (2) Pages from: 20358-1 to: 20358-28
More Information: We thank A. Canali, R. Grimm, S. Meek, D. Petrov, G. Santambrogio, and the LENS Quantum Gases group for fruitful discussions, and G. Rosi and L. Salvi for technical support. We also acknowledge A. Canali for contributions to the experiment, and D. Petrov for sharing unpublished theoretical results. K.Z.-K., M.G. and M.T. acknowledge Poland’s high-performance computing infrastructure PLGrid (HPC Center: ACK Cyfronet AGH) for providing computer facilities and support (computational Grant No. PLG/2023/016115).; This work was supported by the European Research Council under Grant No. 637738, by the EU H2020 Marie Sklodowska-Curie under Grant No. 894442 (CriLiN; fellowship to A.C.), by the National Science Center, Poland under Grants No. 2019/35/N/ST4/04504 and No. 2020/38/E/ST2/00564, by the Italian Ministry of University and Research under PRIN2022 Project No. 20227F5W4N, and, cofunded by the European Union-NextGenerationEU, under the Integrated infrastructure initiative in Photonic and Quantum Sciences (I-PHOQS; CUP B53C22001750006), the PE0000023-NQSTI project, and the Young Researcher Grants No. MSCA_0000042 (PoPaMol; fellowship to A.C.) and No. MSCA_0000048 (MajorSuperQ; fellowship to M.S.).KeyWords: Cold Molecules; Oscillations; Resonances; CollisionsDOI: 10.1103/PRXQuantum.5.020358Citations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-20References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click here