Ex10 25

$\def\abs#1{|#1|}\def\i{\mathbf {i}}\def\ket#1{|{#1}\rangle}\def\bra#1{\langle{#1}|}\def\braket#1#2{\langle{#1}|{#2}\rangle}\def\tr{\mathord{\mbox{tr}}}\mathbf{Exercise\ 10.25}$

Persistency of cluster states

For the cluster state $\ket{\phi_N}$ corresponding to the $1\times N$ lattice for $N$ even, give a sequence of $N/2$ single-qubit measurements that result in a completely unentangled state.