Quantum computing may offer an intriguing path for paradigm changes in computational science. Among potential quantum computing applications, simulation of quantum many-body phenomena and learning of quantum states/processes are where we expect to have quantum advantage over classical counterparts in computational resource. In this talk, I will present our recent studies of quantum machine learning including applications to particle physics. While qubit technology is the foundation of quantum computing, it will also provide a means of probing the nature as a quantum sensing device. I will highlight our recent activities of utilizing superconducting qubits to search for dark matter, and the initial findings and prospects in the experiment.