The influence of collision energy on magnetically tuned 6Li-6Li Feshbach resonance

Abstract

The effect of collision energy on the magnetically tuned 6Li–6Li Feshbach resonance (FR) is investigated theoretically by using the coupled-channel (CC) method for the collision energy ranging from 1 μK ⋅ k B to 100 μK ⋅ k B. At the collision energy of 1 μK ⋅ k B, the resonance positions calculated are 543.152 Gs (s wave, the unit 1 Gs = 10−4 T), 185.109 Gs (p wave |ml | = 0), and 185.113 Gs (p wave |ml | = 1), respectively. The p-wave FR near 185 Gs exibits a doublet structure of 4 mGs, associated with dipole–dipole interaction. With the increase of the collision energy, it is found that the splitting width remains the same (4 mGs), and that the resonance positions of s and p waves are shifted to higher magnetic fields with the increase of collision energy. The variations of the other quantities including the resonance width and the amplitude of the total scattering section are also discussed in detail. The thermally averaged elastic rate coefficients at T = 10, 15, 20, 25 K are calculated and compared.