Entangling the optical frequency comb: simultaneous generation of
multiple 2x2 and 2x3 continuous-variable cluster states in a single optical
parametric oscillator
We report on our research effort to generate large-scale multipartite
optical-mode entanglement using as few physical resources as possible. We have
previously shown that cluster- and GHZ-type N-partite continuous-variable
entanglement can be obtained in an optical resonator that contains a suitably
designed second-order nonlinear optical medium, pumped by at most O(N^2)
fields. In this paper, we show that the frequency comb of such a resonator can
be entangled into an arbitrary number of independent 2x2 and 2x3
continuous-variable cluster states by a single optical parametric oscillator
pumped by just a few optical modes.Comment: Third version has corrected eqs. (10-14) and revised notation "Q" in
lieu of "X" for amplitude quadrature operato