Space-Efficient Simulation of Quantum Computers

TL;DR

This paper presents a space-efficient classical simulation method for quantum computers, enabling the simulation of larger quantum circuits with limited memory, demonstrated through the SEQCSim program.

Contribution

It introduces a novel polynomial-space simulation technique for quantum circuits and provides an open-source implementation, expanding the capacity for classical quantum simulation.

Findings

Enables simulation of larger quantum circuits with limited memory

Provides a publicly available C++ simulation tool

Discusses applications in research and education

Abstract

Traditional algorithms for simulating quantum computers on classical ones require an exponentially large amount of memory, and so typically cannot simulate general quantum circuits with more than about 30 or so qubits on a typical PC-scale platform with only a few gigabytes of main memory. However, more memory-efficient simulations are possible, requiring only polynomial or even linear space in the size of the quantum circuit being simulated. In this paper, we describe one such technique, which was recently implemented at FSU in the form of a C++ program called SEQCSim, which we releasing publicly. We also discuss the potential benefits of this simulation in quantum computing research and education, and outline some possible directions for further progress.