Direct observation of atom-ion non-equilibrium sympathetic cooling

Abstract

Sympathetic cooling is the process of energy exchange between a system and a colder bath. We investigate this fundamental process in an atom-ion experiment where the system is composed of a single ion, trapped in a radio-frequency Paul trap, and prepared in a coherent state of ~200 K and the bath is an ultracold cloud of atoms at μK temperature. We directly observe the sympathetic cooling dynamics with single-shot energy measurements during one, to several, collisions in two distinct regimes. In one, collisions predominantly cool the system with very efficient momentum transfer leading to cooling in only a few collisions. In the other, collisions can both cool and heat the system due to the non-equilibrium dynamics of the atom-ion collisions in the presence of the ion-trap's oscillating electric fields. While the bulk of our observations agree well with a molecular dynamics simulation of hard-sphere (Langevin) collisions, a measurement of the scattering angle distribution reveals forward-scattering (glancing) collisions which are beyond the Langevin model. This work paves the way for further non-equilibrium and collision dynamics studies using the well-controlled atom-ion system.

References in corpus (10)

• A trapped single ion inside a Bose-Einstein condensate
• Power-Law Distributions for a Trapped Ion Interacting with a Classical Buffer Gas
• Controlling chemical reactions of a single particle
• Sympathetic cooling of a membrane oscillator in a hybrid mechanical-atomic system
• Fluorescence during Doppler cooling of a single trapped atom
• Kinetics of a single trapped ion in an ultracold buffer gas
• Dynamics of a single ion spin impurity in a spin-polarized atomic bath
• Blue-sky bifurcation of ion energies and the limits of neutral-gas sympathetic cooling of trapped ions
• Experimental apparatus for overlapping a ground-state cooled ion with ultracold atoms
• Single-shot energy measurement of a single atom and the direct reconstruction of its energy distribution

Cited by in corpus (22)

• Cold hybrid ion-atom systems
• Optical Traps for sympathetic Cooling of Ions with ultracold neutral Atoms
• Ionic polaron in a Bose-Einstein condensate
• Cold trapped molecular ions and hybrid platforms for ions and neutral particles
• Observation of Interactions between Trapped Ions and Ultracold Rydberg Atoms
• Phase-locking between different partial-waves in atom-ion spin-exchange collisions
• Experimental apparatus for overlapping a ground-state cooled ion with ultracold atoms
• Observation of trap-assisted formation of atom-ion bound states
• Quantum-Logic Detection of Chemical Reactions
• Effect of ion-trap parameters on energy distributions of ultra-cold atom-ion mixtures
• Charge dynamics of a molecular ion immersed in a Rydberg-dressed atomic lattice gas
• Far-from-equilibrium noise heating and laser cooling dynamics in radio-frequency Paul traps
• Combining experiments and relativistic theory for establishing accurate radiative quantities in atoms: the lifetime of the ${}^2$P${}_{3/2}$ state in ${}^{40}$Ca${}^{+}$
• Strong angular-momentum mixing in ultracold atom-ion excitation-exchange
• Ion-induced interactions in a Tomonaga-Luttinger liquid
• Tuning nonthermal distributions to thermal ones in time-dependent Paul traps
• Interactions and charge transfer dynamics of an Al${}^{+}$ ion immersed in ultracold Rb and Sr atoms
• Ultracold Interactions between Ions and Polar Molecules
• The energy distribution of an ion in a radiofrequency trap interacting with a nonuniform neutral buffer gas
• Quantum suppression of cold reactions far from the s-wave energy limit
• Numerical modeling for trapped-ion thermometry using dark resonances
• The Gross-Pitaevskii-Poisson model for an ultracold plasma: density waves and solitons