/sci/ - Science & Math

>>11656225
>>11657692
As for how we know it was ever an entangled state, well you prepare multiple copies of [math]|\Phi^{+}\rangle[/math] and measure them. Then you look at the empirical distribution of your experiments and determine whether it statistically agrees with the theoretical distribution. See the attached pic, it's the output of one of IBM's older (highly noisy) devices, measuring precisely [math]|\Phi^{+}\rangle[/math]. I don't know how many samples, I just pulled a random image from google. (Note that the device has 4 qubits, though the data is from an experiment that products [math]|\Phi^{+}\rangle[/math], thus only 2 are used.)