Feshbach resonances inHe3*-

Abstract

We discuss the stability of homonuclear and heteronuclear mixtures of 3 He and 4 He atoms in the metastable 2 3 S 1 state (He * ) and predict positions and widths of Feshbach resonances by using the asymptotic-bound-state model. All calculations are performed without fit parameters, using ab initio calculations of molecular potentials. One promising very broad Feshbach resonance ( B = 72.9 +18.3 −19.3 mT) is found that allows for tuning of the interisotope scattering length.

Magnetic-field-dependent trap loss of ultracold metastable helium

“…Finally, in Sec. VI we conclude and give an outlook for using our measured three-body loss rate coefficient in the context of universal theory and for magneticfield-dependent trap losses in ultracold 3 He * -4 He * mixtures, where an 800-G broad Feshbach resonance is predicted [21].…”

“…The authors of Ref. [21] predicted the existence of a d-wave Feshbach resonance, either in a pure m = −1 sample below 470 G or in a pure m = +1 sample below 90 G, by varying the singlet potential within the theoretical bounds. In the latter case the molecular state would be a shape resonance.…”

“…In this paper we present trap loss measurements in 4 He * for single-spin m = +1 and m = −1 clouds, which are expected to show suppression of Penning ionization, for fields up to 450 G. In particular, we have investigated the prediction of a strong magnetic-field dependence of the two-body loss rate for atoms in the m = +1 state [10][11][12], which had not yet been experimentally tested. We have also searched for a d-wave Feshbach resonance, which was recently predicted [21]. This paper is organized as follows.…”

Asymptotic-bound-state model for Feshbach resonances

“…Additionally, we present ABM calculations on the 40 K-87 Rb mixture to demonstrate its validity on a more complex system, comparing it with accurate coupled-channel calculations [12]. The case of metastable helium atoms where each atom has an electron spin of s = 1 and the interaction occurs through singlet, triplet, and quintet interaction potentials we discuss elsewhere [13].…”

“…[9], was successfully applied to the Fermi-Fermi mixture of 6 Li and 40 K. In Ref. [8] the observed loss features were assigned to 13 Feshbach resonances with high accuracy, and the obtained parameters served as an input to a full coupled-channel analysis. The ABM builds on an earlier model by Moerdijk et al [10] for homonuclear systems, which was also applied by Stan et al [11] for heteronuclear systems.…”