  Quantum computers are expected to be more efficient in performing certain
computations than any classical machine. Unfortunately, the technological
challenges associated with building a full-scale quantum computer have not yet
allowed the experimental verification of such an expectation. Recently, boson
sampling has emerged as a problem that is suspected to be intractable on any
classical computer, but efficiently implementable with a linear quantum optical
setup. Therefore, boson sampling may offer an experimentally realizable
challenge to the Extended Church-Turing thesis and this remarkable possibility
motivated much of the interest around boson sampling, at least in relation to
complexity-theoretic questions. In this work, we show that the successful
development of a boson sampling apparatus would not only answer such inquiries,
but also yield a practical tool for difficult molecular computations.
Specifically, we show that a boson sampling device with a modified input state
can be used to generate molecular vibronic spectra, including complicated
effects such as Duschinsky rotations.
