Click here for a printable version of this page.
Atomic Physics Seminars
Quantum Information Seminar
Monday, June 16, 2014
3:30 PM
Physics Building, Room 204
Note special time.

Avi Pe'er
[Host: Olivier Pfister]
Bar Ilan University
"Exploiting the bandwidth resource of broadband biphotons: Efficient detection with a biphoton interferometer"
Slideshow (PDF)

ABSTRACT:
Broadband timeenergy entangled photon pairs (biphotons) from a narrowband pump are in many ways the 'black sheep of the family' in quantum information. Although they are very easily produced in large quantities and demonstrate extreme nonclassical behavior, broadband biphotons are rarely used in quantum information, mainly because of the bandwidth limitations in detecting them with standard photodetectors and homodyne techniques. We demonstrate complete measurement of the biphotons wavefunction (amplitude and phase) with nearunit efficiency, using a quantum interference between the generation amplitudes of biphotons in two separated nonlinear media. I will describe experiments that employ this method with two different ultrabright and ultrabroadband sources of biphotons: one based on spontaneous down conversion (SPDC) in a nonlinear crystal, and the other on spontaneous fourwaves mixing (FWM) in a nonlinear fiber. With SPDC we measure the quantum purity and the spectral phase of the biphoton wavefunction from the observed fringe pattern and its visibility. With the FWM source we explore the quantumtoclassical transition as pump intensity is varied, and observe quantum collapses and revivals of the interference contrast that are the signature of biphoton generation with imaginary gain – a unique quantum regime of FWM.
1. Yaakov Shaked, Roey Pomerantz, Rafi Z. Vered and Avi Pe'er, "Observing the nonclassical nature of ultrabroadband biphotons at ultrafast speed", New J. Phys. 16, 053012 (2014).
2. Rafi Vered, Yaakov Shaked, Michael Rosenbluh and Avi Pe'er, "The ClassicaltoQuantum Transition with Broadband FourWaves Mixing  Observing Biphoton Generation with Real or Imaginary Gain", Submitted (2014)
3. Faina Shikerman and Avi Pe’er, "Sumfrequency generation as a detector of highpower twomode squeezing", Phys. Rev. A. 88, 043808 (2013) 
SLIDESHOW:




To add a speaker, send an email to
physspeakers@Virginia.EDU.
Please include the seminar type (e.g. Atomic Physics Seminars), date, name of the speaker, title of talk, and an abstract (if available).
