I will introduce Quirk, a freely available online tool for classically simulating a computational processor. It uses a GUI for drag-and-drop operations, simulates a gate-level quantum computer with discrete qubits using an efficient back-end that allows simulations processes with up to ~50 qubits. It has pre-built programs for popular algorithms, such as the quantum Fourier transform, Shor’s algorithm, etc. I will discuss some of the background needed to construct simple quantum algorithms and then focus on the quantum Fourier transform, which is predicted to give an exponential speed up in comparison to the classical fast Fourier transform. I will end with a mention of other hardware and simulation tools that can be accessed over the web.
The students taking my Quantum Information Science course in Spring 2018 found this to be a useful tool and I plan on using this more heavily in my futureteaching.