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Title: Positive operator-valued measure for two-photon detection via sum-frequency generation
Spontaneous parametric down conversion (PDC), in the perturbative limit, can be considered as a probabilistic splitting of one input photon into two output photons. Conversely, sum-frequency generation (SFG) implements the reverse process of combining two input photons into one. Here we show that a single-photon projective measurement in the temporal-mode basis of the output photon of a two-photon SFG process affects a generalized measurement on the input two-photon state. We describe the positive operator-valued measure (POVM) associated with such a measurement and show that its elements are proportional to the two-photon states produced by the time-reversed PDC process. Such a detection acts as a joint measurement on two photons and is thus an important component of many quantum information processing protocols relying on photonic entanglement. Using the retrodictive approach, we analyze the properties of the two-photon POVM that are relevant for quantum protocols exploiting two-photon states and measurements.  more » « less
Award ID(s):
1839216
PAR ID:
10285997
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Physical review and Physical review letters index
Volume:
103
ISSN:
0094-0003
Page Range / eLocation ID:
043711
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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