The simulation of photonic quantum computers with non-Gaussian circuit elements
has a high memory usage since the quantum state is usually represented as a
tensor, which scales exponentially in the number of modes in the photonic
circuit. However, this representation turns out to be slow and overabundant in
most cases, forcing us to devise a new strategy for simulating general
non-Gaussian photonic circuits.
In our proposed strategy, the way to cut off the quantum state is more
economical in terms of data, so that the memory usage of the simulation can be
significantly reduced. In our recently developed simulator (called Piquasso) we
implemented this strategy, which enabled us to perform simulations faster than before.