title: Coherent detection of electron dephasing.
abstract: We show that an Aharonov-Bohm ring with asymmetric electron injection can act as a coherent detector of electron dephasing. The presence of a dephasing source in one of the two arms of a moderately-to-highly asymmetric ring changes the response of the system from total reflection to complete transmission while preserving the coherence of the electrons propagating from the ring, even for strong dephasing. We interpret this phenomenon as an implementation of an interaction-free measurement.
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza dei Cavalieri, 7, I-56126 Pisa, Italy. e.strambini@sns.it
authors.forename: E
authors.initials: E
authors.lastname: Strambini
authors.forename: L
authors.initials: L
authors.lastname: Chirolli
authors.forename: V
authors.initials: V
authors.lastname: Giovannetti
authors.forename: F
authors.initials: F
authors.lastname: Taddei
authors.forename: R
authors.initials: R
authors.lastname: Fazio
authors.forename: V
authors.initials: V
authors.lastname: Piazza
authors.forename: F
authors.initials: F
authors.lastname: Beltram