Negatively refracting atomic vapour

Abstract

A new mechanism for realizing negative refractive index with a four-level atomic system is suggested. The explicit expressions for the electric permittivity and magnetic permeability at probe frequency are presented. It is shown that there is a frequency band in which the four-level photonic-resonant atomic vapour may exhibit simultaneously negative permittivity and permeability, and that such an atomic vapour may become a left-handed material (negatively refracting medium). Compared with the previous schemes to realize negative refraction within the framework of classical electromagnetic theory, the most remarkable features of the present scenario are as follows: (i) isotropic material with microscopic structure units at atomic-scale level, (ii) negative refraction in visible and infrared frequency bands, (iii) controllable manipulation by external fields and (iv) based on quantum coherence in a multilevel atomic system.

Coherence-Driven Topological Transition in Quantum Metamaterials

“…More recently, exotic properties such as left-handed electromagnetic responses have been theoretically proposed using dense homogenous atomic vapors with number density N 0 ∼ 10 23 m −3 or higher [17][18][19][20][21]. However, because quantum interference is fragile, the performance of thermal atomic vapors is severely affected by collisional dephasing and Doppler broadening.…”

Negative refraction without absorption via both coherent and incoherent fields in a four-level left-handed atomic system

“…According to the Clausius-Mossotti relations considering the local effect in dense medium [25], the relative permittivity and relative permeability are expressed as [18,26] ε r = 1 + 2 3 Nα e 1− 1 3 Nα e ; ð13Þ…”

Anisotropy of electromagnetically induced left-handedness in atomic three-level media based upon bianisotropic polarizabilities and tensor character

“…This is reasonable, considering that technology is only just beginning to enable movement of single atoms using atomic force microscopes and similar instruments. There is one exception to this trend, and it is in the use of optically activated media using atomic constituents with interrogated energy levels [9][10][11][12][13][14][15][16][17][18]. In this Letter, attention is directed toward one of the work horses in quantum optics, the three-level system.…”