Quantum annealing with spin lock technique*

Quantum annealing (QA) and adiabatic quantum computation (AQC) are attractive ways to tackle combinatorial optimization problems. However, the standard QA and AQC require strong interactions between qubits, and the coupling strength should be comparable with the resonant frequency of the qubits to solve practically useful problems. Such requirement prevents many systems from performing QA and AQC experimentally. Here, we propose an alternative way to implement a spin-lock based QA, which effectively tunes the qubit frequency by a continuous drive. Under the rotating-wave approximation, we show that our method is equivalent to the standard QA and AQC, and moreover we can analyze the deviation of the rotating-wave approximation systematically. Our method can be implemented by many systems such as superconducting transmon qubits, superconducting capacitive shunted flux qubits, and Si quantum-dots-based spin qubits. Since these systems have an advantage in scalability, our results pave the way to implement the practical QA and AQC.