title: Conclusive quantum steering with superconducting transition-edge sensors.
abstract: Quantum steering allows two parties to verify shared entanglement even if one measurement device is untrusted. A conclusive demonstration of steering through the violation of a steering inequality is of considerable fundamental interest and opens up applications in quantum communication. To date, all experimental tests with single-photon states have relied on post selection, allowing untrusted devices to cheat by hiding unfavourable events in losses. Here we close this 'detection loophole' by combining a highly efficient source of entangled photon pairs with superconducting transition-edge sensors. We achieve an unprecedented ∼62% conditional detection efficiency of entangled photons and violate a steering inequality with the minimal number of measurement settings by 48 s.d.s. Our results provide a clear path to practical applications of steering and to a photonic loophole-free Bell test.
authors.affiliation: Centre for Engineered Quantum Systems and Centre for Quantum Computation and Communication Technology (Australian Research Council), University of Queensland, 4072 Brisbane, Queensland, Australia. smith@physics.uq.edu.au
authors.forename: Devin H
authors.initials: DH
authors.lastname: Smith
authors.forename: Geoff
authors.initials: G
authors.lastname: Gillett
authors.forename: Marcelo P
authors.initials: MP
authors.lastname: de Almeida
authors.forename: Cyril
authors.initials: C
authors.lastname: Branciard
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fedrizzi
authors.forename: Till J
authors.initials: TJ
authors.lastname: Weinhold
authors.forename: Adriana
authors.initials: A
authors.lastname: Lita
authors.forename: Brice
authors.initials: B
authors.lastname: Calkins
authors.forename: Thomas
authors.initials: T
authors.lastname: Gerrits
authors.forename: Howard M
authors.initials: HM
authors.lastname: Wiseman
authors.forename: Sae Woo
authors.initials: SW
authors.lastname: Nam
authors.forename: Andrew G
authors.initials: AG
authors.lastname: White