Atom Waveguides

Пань Ичжэ

The subject of the graduate qualification work is «Analysis of the character of radiation transfer in a disordered three-dimensional ensemble of point scatterers in a waveguide». Object of study is waveguide. The aim is exploring the transmission properties of photons between atoms in waveguide. The following tasks were solved: 1. Calculation of the Green matrix for an ensemble of point-like stationary atoms in a waveguide; 2. Analysis of the nature of dipole-dipole interaction between two atoms; 3. Calculation of the dynamics of cooperative spontaneous decay of excited states of atoms in a waveguide; 4. Transition to the regime of stationary excitation of an atomic ensemble. Calculation of stationary amplitudes of singly excited atomic states; 5. Calculation and analysis of the dependence of the transmittance coefficient in the stationary regime on the size of the atomic medium in the waveguide. As a result of the study, we show how changing the size of messy waveguides controls how atoms emit light. These discoveries help us build better light-based computers and sensors. MATLAB is used to calculate and simulate the mathematical model of interatomic radiation transmission in waveguide.

Mingxia Huo, Ying Li

In the system of a waveguide coupled with an array of atoms, we study the absorption and delayed reemission of light. By adjusting energy levels of atoms, we can engineer a dissipation channel of the atomic collective mode coupled to the waveguide, thereby realizing the high-fidelity absorption and delayed reemission. The fidelity reaches 1 under ideal conditions. The displacement of atoms from the ideal distribution reduces the fidelity in a regular waveguide. However, in the chiral waveguide, we find that the fidelity is robust even if atoms are randomly distributed. Such a system can be used as a quantum memory of photons.

Pavel Exner, Petr Šeba, Pavel Šťovíček

Xue Yang, Zhihai Wang

Abstract This paper investigates the dynamics of two two‐level atoms, which simultaneously couple to a quasi‐1D waveguide with rectangular cross section. The waveguide modes serve as environment, which induces the interaction and collective dissipation between the two distant atoms. When both of the two atoms are located in the middle of the waveguide, a retardation effect is observed, which can be broken by moving one of the atoms away from the center of the waveguide. To preserve the complete dissipation of the system via dark state mechanism, a scheme where the connection of the atoms is perpendicular to the axis of the waveguide is proposed.

Pavel Exner, Hynek Kovařík