- #51

Fredrik

Staff Emeritus

Science Advisor

Gold Member

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I think this is a plausible interpretation of the problem: Find a unitary U such that ##U|+\rangle=|\chi\rangle##. Then find ##

___B## and verify that ##[U^*]_B[\rho]_B__

___B## is diagonal.__

That second part can be done by explicitly doing the matrix multiplication, or by proving the formula ##[\rho]_{B'}=[U^*]_B[\rho]_BThat second part can be done by explicitly doing the matrix multiplication, or by proving the formula ##[\rho]_{B'}=[U^*]_B[\rho]_B

___B## for arbitrary bases B and B'.__