 
Summary: The Computational Complexity of Linear Optics #
Scott Aaronson +
MIT
Alex Arkhipov #
MIT
ABSTRACT
We give new evidence that quantum computersmoreover,
rudimentary quantum computers built entirely out of linear
optical elementscannot be e#ciently simulated by classical
computers. In particular, we define a model of computa
tion in which identical photons are generated, sent through
a linearoptical network, then nonadaptively measured to
count the number of photons in each mode. This model
is not known or believed to be universal for quantum com
putation, and indeed, we discuss the prospects for realizing
the model using current technology. On the other hand,
we prove that the model is able to solve sampling problems
and search problems that are classically intractable under
plausible assumptions.
Our first result says that, if there exists a polynomialtime
