Measuring entangled qutrits and their use for quantum bit commitment.
We produce and holographically measure entangled qudits encoded in transverse spatial modes of single photons. With the novel use of a quantum state tomography method that only requires two-state superpositions, we achieve the most complete characterization of entangled qutrits to date. Ideally, entangled qutrits provide better security than qubits in quantum bit commitment: we model the sensitivity of this to mixture and show experimentally and theoretically that qutrits with even a small amount of decoherence cannot offer increased security over qubits.
Department of Physics, University of Queensland, Brisbane, QLD 4072, Australia.
N K
NK
Langford
R B
RB
Dalton
M D
MD
Harvey
J L
JL
O'Brien
G J
GJ
Pryde
A
A
Gilchrist
S D
SD
Bartlett
A G
AG
White