Boosting linear-optical Bell measurement success probability with predetection squeezing and imperfect photon-number-resolving detectors
AffiliationUniv Arizona, Coll Opt Sci
MetadataShow full item record
PublisherAMER PHYSICAL SOC
CitationKilmer, T., & Guha, S. (2019). Boosting linear-optical Bell measurement success probability with predetection squeezing and imperfect photon-number-resolving detectors. Physical Review A, 99(3), 032302.
JournalPHYSICAL REVIEW A
Rights©2019 American Physical Society
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractLinear-optical realizations of Bell state measurement (BSM) on two single-photon qubits succeed with probability p(s) no higher than 0.5. However, predetection quadrature squeezing, i.e., quantum noise limited phase sensitive amplification, in the usual linear-optical BSM circuit, can yield p(s) approximate to 0.643. The ability to achieve p(s) > 0.5 has been found to be critical in resource-efficient realizations of linear-optical quantum computing and all-photonic quantum repeaters. Yet, the aforesaid value of p(s) > 0.5 is not known to be the maximum achievable using squeezing, thereby leaving it open whether close-to-100% efficient BSM might be achievable using squeezing as a resource. In this paper, we report insights on why squeezing-enhanced BSM achieves p(s) > 0.5. Using this, we show that the previously reported p(s )0.643 at single-mode squeezing strength r = 0.6585-for unambiguous state discrimination (USD) of all four Bell states-is an experimentally unachievable point result, which drops to p(s )approximate to 0.59 with the slightest change in r. We, however, show that squeezing-induced boosting of p(s) with USD operation is still possible over a continuous range of r, with an experimentally achievable maximum occurring at r = 0.5774, achieving p(s) approximate to 0.596. Finally, deviating from USD operation, we explore a trade space between P-s, the probability with which the BSM circuit declares a "success," versus the probability of error P-e, the probability of an input Bell state being erroneously identified given the circuit declares a success. Since quantum error correction could correct for some P-e > 0, this tradeoff may enable better quantum repeater designs by potentially increasing the entanglement generation rates with p(s) exceeding what is possible with traditionally studied USD operation of BSMs.
VersionFinal published version
SponsorsNSF subaward of a Yale University led project