Generation of hyperentangled photon pairs.
We experimentally demonstrate the first quantum system entangled in every degree of freedom (hyperentangled). Using pairs of photons produced in spontaneous parametric down-conversion, we verify entanglement by observing a Bell-type inequality violation in each degree of freedom: polarization, spatial mode, and time energy. We also produce and characterize maximally hyperentangled states and novel states simultaneously exhibiting both quantum and classical correlations. Finally, we report the tomography of a 2 x 2 x 3 x 3 system (36-dimensional Hilbert space), which we believe is the first reported photonic entangled system of this size to be so characterized.
Barreiro
Julio T
JT
Department of Physics, University of Illinois at Urbana-Champaign, 61801-3080, USA.
Langford
Nathan K
NK
Peters
Nicholas A
NA
Kwiat
Paul G
PG