Terry Rudolph, Barry C. Sanders
Requirement of Optical Coherence for Continuous--Variable Quantum Teleportation
Preprint series: ESI preprints

MSC:

81V80 Quantum optics

PACS: 03.65.Bz,02.20.-a,42.50.-p
Abstract: We show that the sender (Alice) and the receiver (Bob) each require coherent
devices in order to achieve unconditional continuous variable
quantum teleportation (CVQT), and this requirement cannot be achieved with
conventional laser sources, even in principle. The appearance of successful
CVQT in recent experiments is due to interpreting the measurement record
fallaciously in terms of one preferred ensemble (or decomposition) of the
correct density matrix describing the state. Our analysis is unrelated to
technical problems such as laser phase drift or finite squeezing bandwidth.