  The fully self-consistent Hartree-Fock (HF) plus random phase approximation
(RPA) based on Skyrme-type interaction is used to study the existence problem
of proton semi-bubble structure in the $2_1^+$ state of $^{34}$Si. The
experimental excitation energy and the B(E2) strength of the $2_1^+$ state in
$^{34}$Si can be reproduced quite well. The tensor effect is also studied. It
is shown that the tensor interaction has a notable impact on the excitation
energy of the $2_1^+$ state and a small effect on the B(E2) value. Besides, its
effect on the density distributions in the ground and $2_1^+$ state of
$^{34}$Si is negligible. Our present results with T36 and T44 show that the
$2_1^+$ state of $^{34}$Si is mainly caused by proton transiton from $\pi
1d_{5/2}$ orbit to $\pi 2s_{1/2}$ orbit, and the existence of a proton
semi-bubble structure in this state is very unlikely.
