  We prove that 2-Local Hamiltonian (2-LH) with Low Complexity problem is
QCMA-complete by combining the results from the QMA-completeness[4] of 2-LH and
QCMA-completeness of 3-LH with Low Complexity[6]. The idea is straightforward.
It has been known that 2-LH is QMA-complete. By putting a low complexity
constraint on the input state, we make the problem QCMA. Finally, we use
similar arguments as in [4] to show that all QCMA problems can be reduced to
our proposed problem.
