Quantum++: A modern C++ quantum computing library

TL;DR

Quantum++ is a versatile, high-performance C++ library for simulating quantum systems and classical reversible logic, emphasizing ease of use, portability, and broad applicability in quantum computing research.

Contribution

It introduces a modern, multi-threaded C++11 library capable of simulating arbitrary quantum processes without restrictions to qubit systems or specific tasks.

Findings

Simulates 25 qubits in pure states efficiently

Handles 12 qubits in mixed states reasonably fast

Supports classical reversible logic operations on billions of bits

Abstract

Quantum++ is a modern general-purpose multi-threaded quantum computing library written in C++11 and composed solely of header files. The library is not restricted to qubit systems or specific quantum information processing tasks, being capable of simulating arbitrary quantum processes. The main design factors taken in consideration were the ease of use, portability, and performance. The library's simulation capabilities are only restricted by the amount of available physical memory. On a typical machine (Intel i5 8Gb RAM) Quantum++ can successfully simulate the evolution of 25 qubits in a pure state or of 12 qubits in a mixed state reasonably fast. The library also includes support for classical reversible logic, being able to simulate classical reversible operations on billions of bits. This latter feature may be useful in testing quantum circuits composed solely of Toffoli gates, such as certain arithmetic circuits.