Découverte de l'informatique quantique, état de l'art et tests sur machine IBM
Thomas Cluzel, Claude Mazel, David R.C. Hill · HAL (Le Centre pour la Communication Scientifique Directe) · 2020
The goal of this research report was to draw the state of the art of the advancement in quantum computing as part of a project of the International Master Research of the ISIMA engineering school. To do so, we first studied the principles of quantum physics required to understand quantum computing, namely, quantum superposition, quantum entanglement and wave-function collapse. These principles define a qubit which represents thequantum information. Qubits are, however, limited by decoherence, which prevents them to stay in a superposed state for a long period of time, and the no-cloning theorem, which prevents the copy of the superposed state of a qubit. We can interact with qubits thanks to quantum gates which composed quantum circuits. Throughout this project, we analysed Grover’s algorithm which is a quantum search algorithm. Then, we implemented it with Qiskit, a Python’s library developed by IBM. Eventually, we executed it on a real quantum computer available on IBM Q Experience and we found reproducibility issues. Today, quantum computers cannot handle many qubits nor apply many quantum gates, but it was enough for Google to claim to have reached quantum supremacy in October 2019.