p-wave superfluidity and BCS-BEC crossover of ultracold polar molecules

ongoing

P-wave superfluids of fermionic particles are a crucial subject of study in condensed matter systems, where fermions pair up with nonzero angular momentum and exotic quantum phenomena like Majorana zero mode are predicted to exist. Investigation into the p-wave superfluids not only helps unravel the underlying mechanism of high-T superconductors but also provides insights into the fundamental symmetry of elementary particles. Over the last decade, ultracold quantum gas of polar molecules with controllable long-range dipolar interaction has emerged to be a powerful testbed to investigate such exotic quantum phases. At sufficiently low temperatures, fermionic molecules can pair up with p-wave symmetry and form a many-body BCS state. With the molecular scattering controlled with field-link resonances, the BCS-BEC crossover of diatomic molecules can be achieved. However, cooling of these fermionic molecules to this regime and the detection of their emerging properties remains challenging. The main goal of MolPWSupFluid project is to cool polar fermionic NaK molecules to unprecedentedly low temperatures and study the many-body behavior with strong dipolar interaction including p-wave superfluidity and their crossover to a Bose-Einstein condensate of tetratomic molecules. This project will focus on technical advancements in microwave field control, enabling state-of-the-art evaporative cooling of dipolar molecules and facilitating the precise manipulation of molecular scattering with microwave-induced field-link resonances. With successful cooling of the NaK molecules below the superfluid critical temperature, we will investigate the anisotropic pairing property and the Higgs mode excitation of the molecules with critical velocity and Bragg spectroscopy. Finally, we will investigate the topological property of vortex in the p-wave superfluid and the non-Abelian statistics of Majorana zero modes with braiding operations.