Generation of nonclassical biphoton states through cascaded quantum walks on a nonlinear chip

Alexander S. Solntsev*, Frank Setzpfandt, Alex S. Clark, Che Wen Wu, Matthew J. Collins, Chunle Xiong, Andreas Schreiber, Fabian Katzschmann, Falk Eilenberger, Roland Schiek, Wolfgang Sohler, Arnan Mitchell, Christine Silberhorn, Benjamin J. Eggleton, Thomas Pertsch, Andrey A. Sukhorukov, Dragomir N. Neshev, Yuri S. Kivshar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

90 Citations (Scopus)
8 Downloads (Pure)


We demonstrate a nonlinear optical chip that generates photons with reconfigurable nonclassical spatial correlations. We employ a quadratic nonlinear waveguide array, where photon pairs are generated through spontaneous parametric down-conversion and simultaneously spread through quantum walks between the waveguides. Because of the quantum interference of these cascaded quantum walks, the emerging photons can become entangled over multiple waveguide positions. We experimentally observe highly nonclassical photon-pair correlations, confirming the high fidelity of on-chip quantum interference. Furthermore, we demonstrate biphoton-state tunability by spatial shaping and frequency tuning of the classical pump beam.

Original languageEnglish
Article number031007
Pages (from-to)031007-1-031007-13
Number of pages13
JournalPhysical Review X
Issue number3
Publication statusPublished - 2014
Externally publishedYes

Bibliographical note

Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


  • Optics
  • Quantum Physics


Dive into the research topics of 'Generation of nonclassical biphoton states through cascaded quantum walks on a nonlinear chip'. Together they form a unique fingerprint.

Cite this