  Quantum computing has potential to provide exponential speedups over
classical computing for many important applications. However, today's quantum
computers are in their early stages, and hardware quality issues hinder the
scale of program execution. Benchmarking and simulation of quantum circuits on
classical computers is therefore essential to advance the understanding of how
quantum computers and programs operate, enabling both algorithm discovery that
leads to high-impact quantum computation and engineering improvements that
deliver to more powerful quantum systems. Unfortunately, the nature of quantum
information causes simulation complexity to scale exponentially with problem
size. In this paper, we debut Super.tech's SuperSim framework, a new approach
for high fidelity and scalable quantum circuit simulation. SuperSim employs two
key techniques for accelerated quantum circuit simulation: Clifford-based
simulation and circuit cutting. Through the isolation of Clifford subcircuit
fragments within a larger non-Clifford circuit, resource-efficient Clifford
simulation can be invoked, leading to significant reductions in runtime. After
fragments are independently executed, circuit cutting and recombination
procedures allow the final output of the original circuit to be reconstructed
from fragment execution results. Through the combination of these two
state-of-art techniques, SuperSim is a product for quantum practitioners that
allows quantum circuit evaluation to scale beyond the frontiers of current
simulators. Our results show that Clifford-based circuit cutting accelerates
the simulation of near-Clifford circuits, allowing 100s of qubits to be
evaluated with modest runtimes.
