Photonic band structure of the three-dimensional88Sratomic lattice

Abstract

Based on the narrow linewidth 1 S 0 -3 P 1 transition of the bosonic 88 Sr atom, we investigate the dispersion relation for light propagating in a three-dimensional (3D) atomic dipolar lattice. Two factors determine the presence of the photonic band gap (PBG): lattice geometry and the atomic polarization. For a two-level atomic system, the former factor plays a major role. An omnidirectional PBG is predicted in the non-Bravais diamond lattice while no PBG exists in the Bravais lattices. However, since a PBG happens around the resonant 1 S 0 -3 P 1 line, the probe beam suffers a significant atomic absorption, which is the major drawback in Bragg scattering. We propose applying an external field to couple the atomic 3 P 1 -3 D 1 transition so as to modify the atomic polarization of the 1 S 0 -3 P 1 transition. In the three level 1 S 0 -3 P 1 -3 D 1 atomic system, the atomic polarization strongly affects the band structure besides the lattice geometry. Dual PBGs can exist in simple cubic and face-centered cubic lattices, but the original PBG, in the diamond lattice composed of the two-level atoms, vanishes. Meanwhile, since two PBGs can be pushed far away from the atomic resonant 1 S 0 -3 P 1 line, the atomic absorption is significantly suppressed, which enhances the reflection efficiency in Bragg scattering.

Quantum simulation with fully coherent dipole--dipole-interactions mediated by three-dimensional subwavelength atomic arrays

“…In this paper, we thus propose to use three-dimensional atomic arrays to engineer omnidirectional bandgaps and furthermore to mediate interactions between impurity atoms. In the past, the occurence of bandgaps in atomic arrays has been discussed in several works [26][27][28][29][30]. However, the diamond lattice so far is the only known atomic array that can host an omnidirectional band gap [31].…”

Spatial Kramers-Kronig relation and controlled unidirectional reflection in cold atoms

“…The reflection control of light signals is usually reciprocal and static (i.e., determined by growth design) as achieved, e.g., via fixed band gaps of photonic crystals possessing certain periodic structures of the real refractive index [9,10]. A tunable photonic band gap has been proved to be viable by establishing controlled periodic structures of the complex susceptibility in the regime of electromagnetically induced transparency (EIT) [11,12], with standing-wave coupling fields to dress homogeneous atomic clouds [13][14][15][16][17] or travelingwave coupling fields to dress periodic atomic lattices [18][19][20][21][22][23][24][25][26][27][28][29]. Generally speaking, it is hard to achieve asymmetric light transport in the familiar linear optical processes [30][31][32], though significant progress has been made in the recent years by considering moving atomic lattices [1,2,28] and fabricating materials of parity-time (PT) symmetry or asymmetry [3,4,33,34].…”