@misc{indiciae47e98cb9a28a,
  title = {Unidirectional Spectral Singularities},
  author = {Ramezani, Hamidreza and Li, Hao-Kun and Wang, Yuan and Zhang, Xiang},
  year = {2014},
  doi = {10.1103/physrevlett.113.263905},
  url = {https://www.osti.gov/biblio/1179991},
  note = {Source identifier: 1179991}
}