Feshbach Spectroscopy of Cs Atom Pairs in Optical Tweezers

Abstract

We prepare pairs of ${}^{133}$Cs atoms in a single optical tweezer and perform Feshbach spectroscopy for collisions of atoms in the states $(f=3,m_f=\pm 3)$. We detect enhancements in pair loss using a detection scheme where the optical tweezers are repeatedly subdivided. For atoms in the state $(3,-3)$, we identify resonant features by performing inelastic loss spectroscopy. We carry out coupled-channel scattering calculations and show that at typical experimental temperatures the loss features are mostly centred on zeroes in the scattering length, rather than resonance centres. We measure the number of atoms remaining after a collision, elucidating how the different loss processes are influenced by the tweezer depth. These measurements probe the energy released during an inelastic collision, and thus give information on the states of the collision products. We also identify resonances with atom pairs prepared in the absolute ground state $(f=3,m_f=3)$, where two-body radiative loss is engineered by an excitation laser blue-detuned from the Cs D${}_2$ line. These results demonstrate optical tweezers to be a versatile tool to study two-body collisions with number-resolved detection sensitivity.

18 pages, 6 figures

References in corpus (11)

• Three-body recombination at large scattering lengths in an ultracold atomic gas
• Energy distribution and cooling of a single atom in an optical tweezer
• Feshbach resonances in ultracold atomic and molecular collisions: threshold behaviour and suppression of poles in scattering lengths
• Feshbach resonances, weakly bound molecular states and coupled-channel potentials for cesium at high magnetic fields
• Molecular assembly of ground state cooled single atoms
• Direct Measurements of Collisional Dynamics in Cold Atom Triads
• Preparation of one ${}^{87}$Rb and one ${}^{133}$Cs atom in a single optical tweezer
• Characterizing Feshbach resonances in ultracold scattering calculations
• Preparation of ${}^{87}$Rb and ${}^{133}$Cs in the motional ground state of a single optical tweezer
• Atomic Clock Measurements of Quantum Scattering Phase Shifts Spanning Feshbach Resonances at Ultralow Fields
• Repeated output coupling of ultracold Feshbach molecules from a Cs BEC

Cited by in corpus (5)

• Quantum simulation of the central spin model with a Rydberg atom and polar molecules in optical tweezers
• Individual assembly of two-species Rydberg molecules using optical tweezers
• Probing the interaction energy of two ${}^{85}$Rb atoms in an optical tweezer via spin-motion coupling
• Formation of ultracold ${}^{39}$K${}^{133}$Cs Feshbach molecules
• Lellouch-Lüscher relation for ultracold few-atom systems under confinement