I want to reproduce the time evolution in this paper in which they are performing a homodyne measurement ‘at y = 0’ (before eq. 3.16). I did not understand how one can perform a homodyne measurement at a value of the position. Can someone explain (including implementation)? Thanks.
Hi @tenebr1s , welcome to the Forum!
It looks to me like they’re doing post-selection.
You can learn about post-selection here. In the example there you will see
MeasureHomodyne(0, select=1) | q[0]
.
If you look at the docs for MeasureHomodyne and compare it with the line of code above, you’ll notice that in this example the measurement angle is 0 (meaning that you’re measuring in the X basis), the desired value of measurement result is 1, and this measurement is being done on the first qumode (q[0]). This looks a lot like what’s in the paper you shared. I don’t know for sure if this is the case but you can email the authors and ask them too!
I hope this helps.