Cs 62DJ Rydberg-atom macrodimers formed by long-range multipole interaction

Abstract

Long-range macrodimers formed by D-state cesium Rydberg atoms are studied in experiments and calculations. Cesium [62DJ ]2 Rydberg-atom macrodimers, bonded via long-range multipole interaction, are prepared by two-color photo-association in a cesium atom trap. The first color (pulse A) resonantly excites seed Rydberg atoms, while the second (pulse B, detuned by the molecular binding energy) resonantly excites the Rydberg-atom macrodimers below the [62DJ ]2 asymptotes. The molecules are measured by extraction of auto-ionization products and Rydberg-atom electricfield ionization, and ion detection. Molecular spectra are compared with calculations of adiabatic molecular potentials. From the dependence of the molecular signal on the detection delay time, the lifetime of the molecules is estimated to be 3-6 µs.

Deeply bound ( 24DJ+5S1/2 ) Rb87

“…3 are unique for each of the eight (I 2 , F 2 , J)-combinations. The upward trend of the background signal at small detunings is attributed to Rydberg-Rydberg molecules [33]. We assign the most prominent discrete peaks to the deep or shallow potentials of Rydberg-ground molecules, A/C or B/D in Fig.…”

Distinct antiblockade features of strongly interacting Rydberg atoms under a two-color weak excitation scheme

“…We now briefly introduce the theoretical model for calculating the multipole interaction potential of nD J Rydberg states, while details can be found in our previous works [31,32]. As shown in figure 1(a), for two nD J Rydberg atoms, denoted by a and b, with an interatomic separation R along the quantization z-axis, we first assume that (i) their Rydberg electrons have positions r a and r b and (ii) the interatomic distance R is larger than the LeRoy radius R LR [33].…”

“…For all molecular states corresponding to a fixed value of M shown in figure 1(a), only one potential curve exhibits a minimum that could give rise to a bound Rydberg macrodimer [31], while all other potential curves just exhibit the repulsive interactions. For the typical atomic density N∼10 10 cm −3 in a MOT, we have the average interatomic separation R∼4.0 μm, marked by a dashed line in figure 1(b), and thus the repulsive interaction…”

“…This is because only one potential curve shows attractive interaction for every molecule state M, whose strength is much less than the repulsive interactions as shown in figure 1(b). A Rydberg molecular signal will be obtained at the pulse B detuning ∼50 MHz, which is beyond the scope of this work (see [31,32] for details) and thus not shown.…”

Observation of effects due to an atom's electric quadrupole polarizability

“…Second-and higher-order quadrupole responses contribute to inter-atomic [3,4] and inter-molecular interactions [5], and they have been observed as resonance shifts in bulk materials [6]. Quadrupole effects are well-known in ion trapping systems, where strong electric quadrupole fields provide confinement.…”