Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Distilling entanglement from random cascades with partial "which path" ambiguity E. A. Meirom, N. H. Lindner, Y. Berlatzky, E. Poem, N. Akopian, J. E. Avron, and D. Gershoni
 

Summary: Distilling entanglement from random cascades with partial "which path" ambiguity
E. A. Meirom, N. H. Lindner, Y. Berlatzky, E. Poem, N. Akopian, J. E. Avron, and D. Gershoni
Department of Physics, Technion--Israel Institute of Technology, Haifa 32000, Israel
Received 9 July 2007; published 9 June 2008
We develop a framework to calculate the density matrix of a pair of photons emitted in a decay cascade with
partial "which path" ambiguity. We describe an appropriate entanglement distillation scheme which works also
for certain random cascades. The qualitative features of the distilled entanglement are presented in a two
dimensional "phase diagram." The theory is applied to the quantum tomography of the decay cascade of a
biexciton in a semiconductor quantum dot. Agreement with experiment is obtained.
DOI: 10.1103/PhysRevA.77.062310 PACS number s : 03.67.Mn, 03.65.Ud, 03.65.Wj, 78.67.Hc
I. INTRODUCTION
Two photon cascades with multiple decay paths are can-
didate sources of entangled pairs of photons. Practical imple-
mentations of quantum-information theory 1,2 prefer to
deal with qubits that are based only on the photons' states of
polarization 35 . Unfortunately, unless the cascade obeys
restrictive symmetry conditions, the two-qubit state associ-
ated with the polarization of the photon pair is mixed and has
negligible entanglement. As these symmetry conditions are
very hard to achieve, a distillation procedure is needed in

  

Source: Avron, Joseph - Physics Department, Technion, Israel Institute of Technology

 

Collections: Physics