  Black-box quantum-state preparation is a variant of quantum-state preparation
where we want to construct an $n$-qubit state $|\psi_c\rangle \propto \sum_x
c(x) |x\rangle$ with the amplitudes $c(x)$ given as a (quantum) oracle. This
variant is particularly useful when the quantum state has a short and simple
classical description. We use recent techniques, namely quantum signal
processing (QSP) and quantum singular value transform (QSVT), to construct a
new algorithm that prepares $|\psi_c\rangle$ without the need to carry out
coherent arithmetic. We then compare our result with current state-of-the-art
algorithms, showing that a QSVT-based approach achieves comparable results.
