Research project A08 – SFB 1227 DQ-mat – Leibniz University Hannover

Introduction

The field of ultracold polar molecules has made significant progress in recent years, offering promising opportunities for the study of quantum phenomena and fundamental physics. The production of ultracold molecules has moved from an ambitious theoretical concept to a practical reality. This progress has largely been achieved by two techniques: the assembly of molecules from ultracold atoms and direct laser cooling of selected molecular species. Ultracold polar molecules have permanent electric dipole moments that give them unique properties, making them invaluable tools for exploring new frontiers in quantum physics, chemistry and quantum information science. Despite these advances, much remains to be explored, in particular pathways to quantum degeneracy or few-body and many-body quantum many-body quantum states arising from dipolar interactions between molecules. This research aims to investigate the prospects of using laser-cooled ultracold polar molecules of CaF for the study of dipolar few-body systems.

Objectives

In the next funding period we will focus on implementing a bottom-up approach to dipolar physics using polar molecules. Among the various possibilities, laser-cooled molecules in particular stand out as promising. Their unique properties offer the potential for direct detection of individual molecules by fluorescence detection on quasi-closed optical transitions. This in turn allows for the possibility of assembling a defect-free array of molecules by re-arrangement, or to deterministically know the number of molecules in the system. By exploiting these advantages we aim to prepare ever larger molecular systems in single optical tweezers in order to study the details of two- and three-body interactions between molecules, to explore possibilities for the controlled preparation of polyatomic molecules from controlled intermolecular collisions, and to study few-body bound states arising from the dipolar interaction. We also plan to gain insight into phenomena such as quantum magnetism and frustration through the preparation and study of precisely controlled small unit cells of molecules prepared using optical tweezer arrays. Studying these systems with a small number of molecules provides a unique opportunity to build precisely controlled, clean, dipolar quantum systems in a bottom-up approach, to explore fundamental aspects of quantum mechanics, and to gain deeper insights into the rich physics of dipolar interactions.