Observation of Feshbach resonances between a single ion and ultracold atoms

Quantum-limited thermometry of a Fermi gas with a charged spin particle

“…Here, α is the (static) polarizability of the atom, e is the elementary electronic charge (i.e., only singly ionized atoms) and 0 the vacuum permittivity. We note that recently Feshbach resonances in hybrid atom-ion systems have been observed [22], thus providing the perspective to control (magnetically) the interspecies interactions. The potential (1) introduces two more length and energy scales: R = (2µ red C 4 / 2 ) 1/2 and E = 2 /[2µ red (R ) 2 ] with µ red = mM/(m + M ) being the reduced atom-ion mass and M is the ion mass.…”

“…Albeit not yet mature as the neutral counterpart, an important experimental effort has been undertaken to immerse charged impurities such as ions in quantum gases [17][18][19]. Sympathetic cooling of ions in a Fermi gas with calcium ions has been experimentally investigated [20], which culminated with the approach of the s-wave regime of atom-ion collisions [21,22]. In addition to the aforementioned out-of-equilibrium phenomena, ions in a 1D fermionic bath have been proposed to study induced interactions in a Li-Yb + mixture [23] (see also Ref.…”

Interactions of Ions and Ultracold Neutral Atom Ensembles in Composite Optical Dipole Traps: Developments and Perspectives

“…On the other hand, using fermions as a bath may allow to suppress three-body recombination events, allowing for much longer interaction times. In addition, due to the unusually large ion-toatom mass ratio, the impact of micromotion-induced heating is expected to be substantially mitigated [24], similar to the 6 Li− 171 Yb + and 6 Li− 138 Ba + systems where sympathetic cooling was demonstrated recently [15,18]. This may enable pre-cooling Ba + to lower energies in the hybrid trap which then would allow for optical trapping at much lower laser intensities.…”

“…The study of interactions between neutral atoms and ions is a highly topical and promising area of research at the intersection of several disciplines including atomic physics, chemistry and quantum simulations [1][2][3][4][5][6][7][8][9][10][11][12]. Many current experiments exploit combinations of established trapping methods, building on the concept of ion-atom hybrid traps first demonstrated by Smith et al in 2005 [1], and have revealed interesting effects and phenomena such as sympathetic cooling [4,5,8,9,11,[13][14][15][16][17][18], state-to-state chemistry [19], non-Maxwellian and superstatistical energy distributions [20,21], charge exchange and transfer [22,23], and ionatom Feshbach resonances [18]. Despite this rapid progress, one of the problems encountered in most experiments suitable for studying generic combinations of ion and atom species is related to the fact that they employ rf fields to confine ions.…”

Observation of Chemical Reactions between a Trapped Ion and Ultracold Feshbach Dimers

“…Next, we turn off the magnetic field, which increases the dimer binding energy to a fixed value of about E b /h = 1.38 GHz [10,39], with h being Planck's constant. By ramping to zero field we minimize variations in the molecular ion formation rate [40], as well as quantum effects [11,41]. For all the reported experiments we obtain dimer densities that are less than 10% of the atomic density.…”