Assignment 1    Due Wednesday October 4, in class.

(a) (Practice with bra-ket notation) A is a measurement (Hermitian) operator with eigenvectors yi eigenvalues li. Show that the expected value of a measurement with A when the system is in state y is
Si li |<yi|y>|2 = <y|A|y>

(b) (Practice with single-qubit gates) Let H be the Hadamard gate, and f the phase gate, defined by the 2x2 matrix
     1  0

     0 exp(if)
normalized by 1/Ö2. Show that you can generate the most general state of a single qubit by operating on <0| with H, followed by a phase gate, followed by an H, followed by a phase gate. The phases of the phase gates are for you to determine.