Memory-enhanced noiseless cross-phase modulation

Mahdi Hosseini, Stojan Rebić, Ben M. Sparkes, Jason Twamley, Ben C. Buchler, Ping K. Lam*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


Large nonlinearity at the single-photon level can pave the way for the implementation of universal quantum gates. However, realizing large and noiseless nonlinearity at such low light levels has been a great challenge for scientists in the past decade. Here, we propose a scheme that enables substantial nonlinear interaction between two light fields that are both stored in an atomic memory. Semiclassical and quantum simulations demonstrate the feasibility of achieving large cross-phase modulation (XPM) down to the single-photon level. The proposed scheme can be used to implement parity gates from which CNOT gates can be constructed. Furthermore, we present a proof of principle experimental demonstration of XPM between two optical pulses: one stored and one freely propagating through the memory medium.

Original languageEnglish (US)
Article numbere40
JournalLight: Science and Applications
Issue numberDECEMBER
StatePublished - 2012


  • CNOT gate
  • Cross-phase modulation
  • Electromagnetically induced transparency
  • Parity gate
  • Quantum memory

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics


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