Suppressing deleterious effects of spontaneous emission in creating bound states in cold atom continuum

Abstract

In a previous paper [B. Deb and G. S. Agarwal, Phys. Rev. A 90, 063417 (2014)], it was theoretically shown that, magneto-optical manipulation of low energy scattering resonances and atom-molecule transitions could lead to the formation of a bound state in continuum (BIC), provided there is no spontaneous emission. We find that even an exceedingly small spontaneous decay from exited molecular states can spoil the BIC. In this paper, we show how to circumvent the detrimental effect of spontaneous emission by making use of vacuum-induced coherence (VIC) which results in the cancellation or suppression of spontaneous emission. VIC occurs due to the destructive interference between two spontaneous decay pathways. An essential condition for VIC is the non-orthogonality of the transition dipole moments associated with the decays. Furthermore, the interference between decay pathways requires that the spacing between the two decaying states must be comparable to or smaller than the square root of the product of the two spontaneous linewidths. We demonstrate that these conditions can be fulfilled by microwave dressing of two appropriately chosen molecular excited states, opening a promising prospect for the experimental realization of BIC of cold atoms.

arXiv comment15 pages, 5 figures

References in corpus (21)

• Feshbach Resonances in Ultracold Gases
• Resonantly Trapped Bound State in the Continuum Laser
• Feshbach resonances in rubidium 87: Precision measurement and analysis
• Surface bound states in the continuum
• Compact surface Fano states embedded in the continuum of waveguide arrays
• Observation of an orbital interaction-induced Feshbach resonance in 173-Yb
• Controlling a magnetic Feshbach resonance with laser light
• A strongly interacting gas of two-electron fermions at an orbital Feshbach resonance
• Long-lived quasi-stationary coherences in V-type system driven by incoherent light
• Bound States in the Continuum Realized in the One-Dimensional Two-Particle Hubbard Model with an Impurity
• Bound states in continuum in an electron waveguide
• Resonant Control of Interaction Between Different Electronic States
• Controlling Directionality and Dimensionality of Wave Propagation through Separable Bound States in the Continuum
• Open quantum dots: resonances from perturbed symmetry and bound states in strong magnetic fields
• Long-lived quantum coherences in a V-type system strongly driven by a thermal environment
• On the ubiquity of Beutler-Fano profiles: from scattering to dissipative processes
• Creation and manipulation of bound states in continuum with lasers: Applications to cold atoms and molecules
• Vacuum-Induced Coherence in Ultracold Photoassociative Ro-Vibrational Excitations
• Optical Feshbach resonances through a molecular dark state: Efficient manipulation of $p$-wave resonances in fermionic ${}^{171}$Yb atoms
• Two-dimensional Fano lineshapes: Excited-state absorption contributions
• Probing vacuum-induced coherence via magneto-optical rotation in molecular systems