Quasim: Quantum Circuit Simulation - Design and Implementation of a Rust library enabling construction, inspection and execution of quantum circuits

Abstract

Quantum computing is becoming more prominent around the world, bringing new approaches to solving computationally difficult problems. The basic computational unit of quantum computers is called qubit. Because qubits can exist in a super-position of both 0 and 1 simultaneously, quantum computers have the capacity to let us execute algorithms that are orders of magnitude faster than their classical counterpart. In this thesis, a quantum circuit simulator is developed as a library for the Rust programming language. This library supports multiple interchangeable simulation backends suited for different quantum circuit computation tasks. The library provides a programming interface for creating quantum circuits, enabling users to con struct and simulate quantum algorithms using the provided simulation backends. For backends that support it, a terminal debugging interface lets users inspect qubit states at each stage of an algorithm. The work focuses on optimization strategies for simulation backends and their comparative performance. The result shows certain simulators can be constructed which excel at simulation of specific circuit configurations, while still subject to the exponential time complexity in the worst case scenario. GPU hardware acceleration proves advantageous for simulating large circuits.