  It has been shown that the Metropolis algorithm can be implemented on quantum
computers in a way that avoids the sign problem. However, flat histogram
techniques are often preferred as they don't suffer from the same limitations
that afflict Metropolis for problems of real-world interest and provide a host
of other benefits. In particular, the Wang-Landau method is known for its
efficiency and accuracy. In this work we design, implement, and validate a
quantum algorithm for Wang-Landau sampling, greatly expanding the range of
quantum many body problems solvable by Monte Carlo simulation.
