  We explore the power of the unbounded Fan-Out gate and the Global Tunable
gates generated by Ising-type Hamiltonians in constructing constant-depth
quantum circuits, with particular attention to quantum memory devices. We
propose two types of constant-depth constructions for implementing Uniformly
Controlled Gates. These gates include the Fan-In gates defined by
$|x\rangle|b\rangle\mapsto |x\rangle|b\oplus f(x)\rangle$ for $x\in\{0,1\}^n$
and $b\in\{0,1\}$, where $f$ is a Boolean function. The first of our
constructions is based on computing the one-hot encoding of the control
register $|x\rangle$, while the second is based on Boolean analysis and
exploits different representations of $f$ such as its Fourier expansion. Via
these constructions, we obtain constant-depth circuits for the quantum
counterparts of read-only and read-write memory devices -- Quantum Random
Access Memory (QRAM) and Quantum Random Access Gate (QRAG) -- of memory size
$n$. The implementation based on one-hot encoding requires either
$O(n\log{n}\log\log{n})$ ancillae and $O(n\log{n})$ Fan-Out gates or
$O(n\log{n})$ ancillae and $6$ Global Tunable gates. On the other hand, the
implementation based on Boolean analysis requires only $2$ Global Tunable gates
at the expense of $O(n^2)$ ancillae.
