@article {1507,
title = {Coulomb bound states of strongly interacting photons},
journal = {Physical Review Letters},
volume = {115},
year = {2015},
month = {2015/09/16},
pages = {123601},
abstract = { We show that two photons coupled to Rydberg states via electromagnetically
induced transparency can interact via an effective Coulomb potential. This
interaction gives rise to a continuum of two-body bound states. Within the
continuum, metastable bound states are distinguished in analogy with
quasi-bound states tunneling through a potential barrier. We find multiple
branches of metastable bound states whose energy spectrum is governed by the
Coulomb potential, thus obtaining a photonic analogue of the hydrogen atom.
Under certain conditions, the wavefunction resembles that of a diatomic
molecule in which the two polaritons are separated by a finite "bond length."
These states propagate with a negative group velocity in the medium, allowing
for a simple preparation and detection scheme, before they slowly decay to
pairs of bound Rydberg atoms.
},
doi = {10.1103/PhysRevLett.115.123601},
url = {http://arxiv.org/abs/1505.03859v1},
author = {Mohammad F. Maghrebi and Michael Gullans and P. Bienias and S. Choi and I. Martin and O. Firstenberg and M. D. Lukin and H. P. B{\"u}chler and Alexey V. Gorshkov}
}