Abstracting Entanglement

In quantum computation, entanglement is a fundamental phenomenon that significantly affects the behaviour and correctness of quantum programs. One of the most striking effects of such a phenomenon arises from its interplay with quantum measurement. A non-classical correlation between the entangled qubits, which is related to a non-local action, makes the measurement of one qubit of an entangled pair instantaneously affect also the other. This leads to potential problems in the execution of a quantum program where variables become entangled during a computation since unintended measurements may cause erroneous results. A static analysis detecting such critical situations is, therefore, necessary to guarantee the correct execution of a quantum program. To pursue this objective, we introduce a novel abstract domain specifically designed to analyse and manage entanglement in quantum programs.