F. Arute et al, "Quantum Supremacy Using a Programmable Superconducting Processor", Nature 574, 505, (2019).qsim is a Schrödinger full state-vector simulator. It computes all the 2n amplitudes of the state vector, where n is the number of qubits. Essentially, the simulator performs matrix-vector multiplications repeatedly. One matrix-vector multiplication corresponds to applying one gate.The total runtime is proportional to g2n, where g is the number of 2-qubit gates. To speed up the simulator, we use gate fusion [2] [3], single precision arithmetic, AVX/FMA instructions for vectorization and OpenMP for multi-threading.
M. Smelyanskiy, N. P. Sawaya, A. Aspuru-Guzik, "qHiPSTER: The Quantum High Performance Software Testing Environment", arXiv:1601.07195 (2016).
T. Häner, D. S. Steiger, "0.5 Petabyte Simulation of a 45-Qubit Quantum Circuit", arXiv:1704.01127 (2017).
You can find documentation on the module, with the command:
module help qsimcirq
The manual is on the web at the original home page (https://pypi.org/project/qsimcirq/)
CINECA consultants can be reached through the address: superc@cineca.it