TY - JOUR
T1 - Kohn-Sham approach to quantum electrodynamical density-functional theory: Exact time-dependent effective potentials in real space
JF - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Y1 - 2015
A1 - Flick, Johannes
A1 - Ruggenthaler, Michael
A1 - Appel, Heiko
A1 - Rubio, Angel
KW - photon matter correlations
KW - quantum electrodynamical density functional theory
KW - quantum electrodynamics
KW - strong light matter interaction
KW - time-dependent density functional theory
AB - The density-functional approach to quantum electrodynamics extends traditional density-functional theory and opens the possibility to describe electron-photon interactions in terms of effective Kohn-Sham potentials. In this work, we numerically construct the exact electron-photon Kohn-Sham potentials for a prototype system that consists of a trapped electron coupled to a quantized electromagnetic mode in an optical high-Q cavity. Although the effective current that acts on the photons is known explicitly, the exact effective potential that describes the forces exerted by the photons on the electrons is obtained from a fixed-point inversion scheme. This procedure allows us to uncover important beyond-mean-field features of the effective potential that mark the breakdown of classical light-matter interactions. We observe peak and step structures in the effective potentials, which can be attributed solely to the quantum nature of light; i.e., they are real-space signatures of the photons. Our findings show how the ubiquitous dipole interaction with a classical electromagnetic field has to be modified in real space to take the quantum nature of the electromagnetic field fully into account.
PB - NATL ACAD SCIENCES
CY - 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA
VL - 112
ER -