Light slowdown in the vicinity of cross-over resonances

Ultracold bosons in the vicinity of a narrow resonance: shallow dimer and recombination

The different resonant regimes that can be achieved by using a magnetic Feshbach resonance are analyzed with a separable two-channel model. Emphasis is put on the case of narrow resonances in a region of intermediate detuning where a shallow dimer exists and an approximate law including the background scattering length for the three-body recombination rate is derived.

Entanglement dynamics of two two-level atoms in the vicinity of an invisibility cloak

We study the entanglement between two identical two-level atoms located near an ideal model of invisibility cloaks, by monitoring the the time evolution of the concurrence measure. We obtain the reduced density operator of the atomic subsystem based on a canonical quantization scheme presented for the electromagnetic field interacting with atomic systems in the presence of an anisotropic, inhomogeneous and absorbing magnetodielectric medium. It is shown that two atoms, which are prepared initially in an unentangled state, are correlated in weak coupling regime via the spontaneous emission and …

Impurity with a resonance in the vicinity of the Fermi energy

We study an impurity with a resonance level whose energy coincides with the Fermi energy of the surrounding Fermi gas. An impurity causes a rapid variation of the scattering phase shift for fermions at the Fermi surface, introducing a new characteristic length scale into the problem. We investigate manifestations of this length scale in the self-energy of the impurity and in the density of the bath. Our calculations reveal a model-independent deformation of the density of the Fermi gas, which is determined by the width of the resonance. To provide a broader picture, we investigate time evoluti…

Efimov scenario for overlapping narrow Feshbach resonances

While Efimov physics in ultracold atoms is usually modeled with an isolated Feshbach resonance many real world resonances appear in close vicinity to each other and are therefore overlapping. Here we derive a realistic model based on the mutual coupling of an open channel and two closed molecular channels while neglecting short-range physics as permitted by the narrow character of the considered resonances. The model is applied to three distinct scenarios with experimental relevance. We show that the effect of overlapping resonances is manifested most strikingly at a narrow resonance in whose …

弯曲时空场论的极化激元模拟器中的受激霍金效应与准正模共振

Stimulated Hawking effect and quasinormal mode resonance in a polariton simulator of field theory on curved spacetime

本研究通过极化激元模拟器数值探究受激霍金效应，构建含视界附近准正模的实验可行有效时空，发现受激霍金效应对应负能量Bogoliubov通道传输且在QNM频率达峰，为相关实验与弯曲时空量子场论研究提供参考。

Efimov resonance position near a narrow Feshbach resonance in $^6$Li-$^{133}$Cs mixture

In the vicinity of a narrow Feshbach resonances Efimov features are expected to be characterized by the resonance's properties rather than the van der Waals length of the interatomic potential. Although this theoretical prediction is well-established by now, it still lacks experimental confirmation. Here, we apply our recently developed three-channel model [Yudkin and Khaykovich, Phys. Rev. A 103, 063303 (2021)] to the experimental result obtained in a mass-imbalanced $^6$Li-$^{133}$Cs mixture in the vicinity of the narrowest resonance explored to date [Johansen at. al. Nat. Phys. 13, 731 (201…