  Grover's quantum search algorithm promises a quadratic speedup for
unstructured search over its classical counterpart. But this advantage is
gradually reduced with noise acting on the search space. In this article, we
demonstrate that a quantum switch can act as a resource operation in mitigating
the effect of the noise in the search space. In this scenario, fault-tolerant
model quantum computing is costly. In addition to the noise modeled by a
depolarizing channel, which coherently acts on the entire quantum register,
such an error correction method can not be trivially implemented. We show that
a quantum switch can significantly add value by reducing this error. In
particular, we propose two frameworks for the application of switches. In the
first framework, we apply the superposition of channels' orders in the form of
a switch and do a post-selection at every iteration of the applications of the
Grover operator. In the second framework, we delay the post-selection until the
very end. In other words, if we want to look at the switch's action at the kth
step, we already have k-1 post-selection measurements in place for the first
framework. In the second case, we only have a single measurement. The number of
post selections is minimal in the second scenario, so its effect is more
credited to the switch. It also gives a significant advantage regarding the
success probability of Grover's algorithm. We take the success probability as
the sole quantifier of the switch's action in diminishing the effect of noise
in search space.
