报告题目：Generating a bound state in continuum for ultracold atoms: Optical manipulation of atom-atom interactions

报 告 人：Bimalendu Deb, Indian Association for the Cultivation of Science

报告时间：2015年10月15日10：30

报告地点：理科楼三楼报告厅（C302）

报告摘要：A bound state in the continuum (BIC) is a counter-intuitive concept first introduced by von Neumann and Wigner more than 80 years ago [1], showing that a BIC can exist due to destructive interference of the outgoing Schroedinger waves scattered by an appropriately designed potential. Over the years, the theoretical approach of von Neumann and Wigner has undergone extensions and modifications [2–4]. In recent times, it has attracted renewed research interest [5] with possible experimental realization [6]. In this talk, we will show that it is possible to generate a BIC in ultracold atoms with lasers in the presence of a magnetic Feshbach resonance [7]. This can be achieved by forming coherent superposition of molecular bound states above the threshold of ground-state atom-atom scattering continuum. Under BIC conditions, the superposition states become effectively decoupled from the continuum, and hence in the absence of other damping processes they are nondecaying. We will discuss its applications in manipulating p-wave optical Feshbach resonances [8, 9] and the formation of Feshbach molecules.

References

[1] J. von Neumann and E. Wigner, Phys. Z. 30, 465 (1929).

[2] L. Fonda and R. G. Newton, Ann. Phys. (NY) 10, 490 (1960).

[3] F. H. Stillinger and D. R. Herrick, Phys. Rev. A 11, 446 (1975).

[4] H. Friedrich and D. Wintgen, Phys. Rev. A 32, 3231 (1985).

[5] A. G. Smart, Phys. Today 66, 14 (2013).

[6] C. W. Hsu et al., Nature (London) 499, 188 (2013).

[7] B. Deb and G. S. Agarwal, Phys. Rev. A 90, 063417 (2014) [Editors' suggestion].

[8] R. Yamazaki, S. Taie, S. Sugawa, K. Enomoto and Y. Takahashi, Phys. Rev. A 87, 010704(R) (2013).

[9] Subrata Saha, Arpita Rakshit, Debashree Chakraborty, Arpita Pal, and Bimalendu Deb, Phys. Rev. A 90, 012701 (2014).