Spectrum of Light in a Quantum Fluctuating Periodic Structure

Mauro Antezza (1) , Yvan Castin (1)

1 LKB (Lhomond) - Laboratoire Kastler Brossel

We address the general problem of the excitation spectrum for light coupled to scatterers having quantum fluctuating positions around the sites of a periodic lattice. In addition to providing an imaginary part to the spectrum, we show that these quantum fluctuations affect the real part of the spectrum, in a way that we determine analytically. Our predictions may be observed with ultracold atoms in an optical lattice, on a J=0->J'=1 narrow atomic transition. As a side result, we resolve a controversy for the occurrence of a spectral gap in a fcc lattice.

Mots clés: light propagation; optical lattices; ultracold atoms

Domaines: Autre [cond-mat.other]

Mauro Antezza, Yvan Castin. Spectrum of Light in a Quantum Fluctuating Periodic Structure. Physical Review Letters, 2009, 103, pp.123903. ⟨hal-00365761v2⟩