Unconditional verification of quantum computation with classical light

Verification of quantum computation is a task to efficiently check whether an output given from a quantum computer is correct. Existing verification protocols conducted between a quantum computer to be verified and a verifier necessitate quantum communication to unconditionally detect any malicious behavior of the quantum computer solving any promise problem in $\mathsf{B}\mathsf{Q}\mathsf{P}$. In this paper, we remove the necessity of the communication of qubits by proposing a “physically classical” verification protocol in which the verifier just sends coherent light to the quantum computer.