- #1
James2018
- 113
- 11
- TL;DR Summary
- Continuous variable Bell state measurement
There is something I don't understand called CV Bell state measurement.
In these two experiments they get two entangled beams
"by overlapping phase-squeezed light with amplitude squeezed light with a phase difference of pi/2 at a 50-50 beamsplitter"
See Figure 11
https://www.researchgate.net/publication/303852805_On-chip_continuous-variable_quantum_entanglement
and
"We generate a pair of entangled beams from the interference of two amplitude squeezed beams."
https://arxiv.org/pdf/quant-ph/0209001.pdf
Of course, the reason they use non-linear crystals is because this is the way to generate amplitude-squeezed light and phase-squeezed light, which have less amplitude noise or phase noise than a coherent light state.
Also, they swap entanglement between laser light and a mirror generated by radiation pressure to the entanglement between the two mirrors by detecting the interference results after a beamsplitter. If you look at Figure 1, it compares this experiment to the above two.
https://arxiv.org/abs/1508.06462
I do not understand how entanglement can be swapped simply by interference of two light beams that are entangled to something else. Also, I don't see any post-selection being mentioned like I see in polarization entanglement swapping.
In these two experiments they get two entangled beams
"by overlapping phase-squeezed light with amplitude squeezed light with a phase difference of pi/2 at a 50-50 beamsplitter"
See Figure 11
https://www.researchgate.net/publication/303852805_On-chip_continuous-variable_quantum_entanglement
and
"We generate a pair of entangled beams from the interference of two amplitude squeezed beams."
https://arxiv.org/pdf/quant-ph/0209001.pdf
Of course, the reason they use non-linear crystals is because this is the way to generate amplitude-squeezed light and phase-squeezed light, which have less amplitude noise or phase noise than a coherent light state.
Also, they swap entanglement between laser light and a mirror generated by radiation pressure to the entanglement between the two mirrors by detecting the interference results after a beamsplitter. If you look at Figure 1, it compares this experiment to the above two.
https://arxiv.org/abs/1508.06462
I do not understand how entanglement can be swapped simply by interference of two light beams that are entangled to something else. Also, I don't see any post-selection being mentioned like I see in polarization entanglement swapping.