Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Efficiency model in loophole free photon Bell tests

  1. Jan 13, 2016 #1


    User Avatar
    Gold Member

    I would like ask comments about assumed photon detection efficiency model used in these experiments that test Bell inequalities and consequences if it does not hold.

    Detection efficiency is calculated as two-fold coincidence events divided by singles counts (from one side). That method assumes equal nondetection probability for all photons. But if we have different nondetection probabilities some error estimates would come out different.

    I made a simple mathematical test. I compare single sample with identical detection probabilities for all photons and another sample that consists of two subsamples where one has 100% detection probability and the other one has 25% detection probability.
    Code (Text):
    True sample size    single detections    coincidences    detection efficiency
    Sample 1
    160                        120               90              90/120=75%
    Sample 2
    80                         80                80              80/80=100%
    160                        40                10              10/40=25%
    Notice that average efficiency for sample 2 would come out the same as for sample 1 as single counts and coincidences sum up to the same numbers as in sample 1.

    From this example it seems that if detection efficiency model does not hold we can underestimate true sample size and that can spoil some error calculations e.g. double photon rate.
  2. jcsd
  3. Jan 19, 2016 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Efficiency model loophole Date
A Non-standard models in QM Feb 12, 2018
Efficiency of CNOT gates May 1, 2015
Efficiency of non-linear optical device Oct 17, 2014
Bell's inequality when efficiency < 1 Aug 21, 2013
Electron/Hole Effective Mass vs Solar Cell efficiency Sep 9, 2012