title: Coupling and entangling of quantum states in quantum dot molecules.
abstract: We demonstrate coupling and entangling of quantum states in a pair of vertically aligned, self-assembled quantum dots by studying the emission of an interacting electron-hole pair (exciton) in a single dot molecule as a function of the separation between the dots. An interaction-induced energy splitting of the exciton is observed that exceeds 30 millielectron volts for a dot layer separation of 4 nanometers. The results are interpreted by mapping the tunneling of a particle in a double dot to the problem of a single spin. The electron-hole complex is shown to be equivalent to entangled states of two interacting spins.
authors.affiliation: Physikalisches Institut, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany. mbayer@physik.uni-wuerzburg.de
authors.forename: M
authors.initials: M
authors.lastname: Bayer
authors.forename: P
authors.initials: P
authors.lastname: Hawrylak
authors.forename: K
authors.initials: K
authors.lastname: Hinzer
authors.forename: S
authors.initials: S
authors.lastname: Fafard
authors.forename: M
authors.initials: M
authors.lastname: Korkusinski
authors.forename: Z R
authors.initials: ZR
authors.lastname: Wasilewski
authors.forename: O
authors.initials: O
authors.lastname: Stern
authors.forename: A
authors.initials: A
authors.lastname: Forchel