  Eigenstate preparation is ubiquitous in quantum computing, and a standard
approach for generating the lowest-energy states of a given system is by
employing adiabatic state preparation (ASP). In the present work, we
investigate a variational method for determining the optimal scheduling
procedure within the context of ASP. In the absence of quantum error
correction, running a quantum device for any meaningful amount of time causes a
system to become susceptible to the loss of relevant information. Therefore, if
accurate quantum states are to be successfully generated, it is crucial to find
techniques that shorten the time of individual runs during iterations of
annealing. We demonstrate our variational method toward this end by
investigating the hydrogen and P4 molecules, as well as the Ising model problem
on a two-dimensional triangular lattice. In both cases, the time required for
one iteration to produce accurate results is reduced by several orders of
magnitude in comparison to what is achievable via standard ASP. As a result,
the required quantum coherence time to perform such a calculation on a quantum
device becomes much less stringent with the implementation of this algorithm.
In addition, our variational method is found to exhibit resilience against
control errors, which are commonly encountered within the realm of quantum
computing.
