A revised version of the massively parallel simulator of a universal quantum
computer, described in this journal eleven years ago, is used to benchmark
various gate-based quantum algorithms on some of the most powerful
supercomputers that exist today. Adaptive encoding of the wave function reduces
the memory requirement by a factor of eight, making it possible to simulate
universal quantum computers with up to 48 qubits on the Sunway TaihuLight and
on the K computer. The simulator exhibits close-to-ideal weak-scaling behavior
on the Sunway TaihuLight,on the K computer, on an IBM Blue Gene/Q, and on Intel
Xeon based clusters, implying that the combination of parallelization and
hardware can track the exponential scaling due to the increasing number of
qubits. Results of executing simple quantum circuits and Shor's factorization
algorithm on quantum computers containing up to 48 qubits are presented.Comment: Substantially rewritten + new data. Published in Computer Physics
Communicatio