title: Unidirectional spectral singularities.
abstract: We propose a class of spectral singularities emerging from the coincidence of two independent singularities with highly directional responses. These spectral singularities result from resonance trapping induced by the interplay between parity-time symmetry and Fano resonances. At these singularities, while the system is reciprocal in terms of a finite transmission, a simultaneous infinite reflection from one side and zero reflection from the opposite side can be realized.
authors.affiliation: NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Ramezani
authors.affiliation: NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA.
authors.forename: Hao-Kun
authors.initials: HK
authors.lastname: Li
authors.affiliation: NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang