Feshbach resonances in potassium Bose-Bose mixtures

Abstract

We present a detailed study of the scattering properties of ultracold mixtures of bosonic potassium atoms. We locate 20 previously unobserved Feshbach resonances in isotopic 39 K-41 K mixtures. These are assigned to s-wave molecular channels by comparison to an asymptotic bound state model and coupled channels calculations. Additional Feshbach resonances are studied in spin mixtures of a single potassium isotope, both in 39 K and 41 K. In particular, we characterize the parameters of a selected 39 K Feshbach resonance by radio-frequency association of Feshbach molecules. Our results could be exploited to refine the model potentials for potassium scattering. Furthermore, these new Feshbach resonances enlarge the range of experiments possible with degenerate Bose-Bose mixtures.

Supersolid phase of a spin-orbit-coupled Bose-Einstein condensate: A perturbation approach

“…This strategy, which already led to the first successful detection of the stripe phase employing the pseudo-spin states of a superlattice [10], could open realistic perspectives for the observability of the sizable effects predicted in the present work. Another promising strategy is provided by the use of different atomic species, like 39 K, where the availability of Feshbach resonances [58] is opening novel perspectives to increase the critical value of the Raman coupling giving the transition to the plane-wave phase [45].…”

Angular stripe phase in spin-orbital-angular-momentum coupled Bose condensates

“…Near the FR, the intraspecies scattering lengths (a ↑↑ , a ↓↓ ) (65, 100)a 0 are approximately constant as shown in Fig. 4, where a 0 is the Bohr radius, and the interspecies one a ↑↓ can be tuned in a wide range [40,41]. In a realistic quasi-2D harmonic trap with frequencies (ω r , ω z )/2π = (10, 200) Hz and an aspect ratio ω z /ω r = 20, the effective 2D interaction strengths become mg ↑↑ /h 2 = 0.015 and mg ↓↓ /h 2 = 0.023, respectively.…”

“…In Sec. III C a Feshbach resonance of a harmonically trapped SOAMC 41 K gas at a magnetic field B 0 = 51.95 G was utilized where a ↑↑ = 65a 0 and a ↓↓ = 100a 0 are approximately constant near the FR and a ↑↓ can be tuned by FR [40,41] (see also Fig. 4).…”

“…(9), in the δplane. From top to bottom, the interspecies scattering length a ↑↓ /a 0 is tuned to 50, 10, 1, and −62, respectively, via the Feshbach resonance in 41 K atoms [40,41].…”

“…Feshbach resonance of 41 K atoms at a magnetic field about B 0 = 51.95 G, in the vicinity of which the intraspecies scattering lengths a ↑↑ and a ↓↓ are almost constant while the interspecies one a ↑↓ is tunable[40,41].…”