I am looking to implement Quantum PCA from this paper (page 62). They have their code on Github.

I have gone through the paper multiple times but failing to understand how they got numbers (for theta, phi and lambda) on line 6, 7, 10, 11, 12 and 13. I understand classical pre-processing where they calculate covariance matrix, density matrix and purify density matrix. I fail to understand how they get those numbers (for theta, phi and lambda) from purified density matrix.

If anyone can point me on how to calculate theta, phi and lambda.

Thanks in advance!

  • $\begingroup$ related: quantumcomputing.stackexchange.com/q/6236/55 $\endgroup$
    – glS
    Nov 19, 2022 at 12:15
  • $\begingroup$ Thanks! I have seen that post, however, the output that I get doesn't match numbers in Github. So, trying to understand whole procedure to see what am I missing. $\endgroup$
    – Nihir
    Nov 19, 2022 at 20:53
  • $\begingroup$ Do you know what the value of $|\psi\rangle$ is? It looks like it's just creating two copies, as described in the text. $\endgroup$ Nov 29, 2022 at 6:03


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.