  We demonstrate an angular momentum-enhanced protocol that permits an angular
displacement estimation by using tunable squeezed Bell state and parity
detection. We consider the resolution and the sensitivity, super-resolution is
presented along with Heisenberg scaling sensitivity for arbitrary tunable
factor, the tunable factor which can optimize the sensitivity is also
discussed. Additionally, we analyze the advantages of using angular momentum
via considering and comparing simulation results. Under the situation of the
optimal tunable factor, the Heisenberg-limited sensitivity and
$2\left(\ell+1\right)$-fold super-resolution peak with quantum number $\ell$
are achieved.
