Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Minimizing state preparation times in pulse-level variational molecular
  simulations   Quantum simulation on NISQ devices is severely limited by short coherence
times. A variational pulse-shaping algorithm known as ctrl-VQE was recently
proposed to address this issue by eliminating the need for parameterized
quantum circuits, which lead to long state preparation times. Here, we find the
shortest possible pulses for ctrl-VQE to prepare target molecular wavefunctions
for a given device Hamiltonian describing coupled transmon qubits. We find that
the time-optimal pulses that do this have a bang-bang form consistent with
Pontryagin's maximum principle. We further investigate how the minimal state
preparation time is impacted by truncating the transmons to two versus more
levels. We find that leakage outside the computational subspace (something that
is usually considered problematic) speeds up the state preparation, further
reducing device coherence-time demands. This speedup is due to an enlarged
solution space of target wavefunctions and to the appearance of additional
channels connecting initial and target states.

19
The categories of this paper are: eess
18
The categories of this paper are: econ
2
The categories of this paper are: math
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con