论文标题
在强泵场下控制超导量子参数
Controls of a superconducting quantum parametron under a strong pump field
论文作者
论文摘要
在固有频率的大约两倍上泵送的约瑟夫森参数振荡器，称为参数或kerr参数振荡器显示自动振荡。提出了使用自动振荡参数作为QUBIT的量子退火和通用量子计算。然而，泵场下的参数元的控制被哈密顿量中不必要的迅速振荡术语降低，我们称之为非谐振的迅速振荡项（NROT）来自违反旋转波近似的侵犯。因此，泵场可以是参数元控制不完美的内在起源。在这里，我们从理论上研究了Nrots对参数控制的准确性的影响：猫态创建和单量门。结果表明，在常规方法中，抑制非绝热过渡的抑制与旋转波近似的有效性之间存在权衡关系。我们还表明，泵场失学的定制时间依赖性可以抑制由于NROT而引起的非绝热过渡和参数状态的干扰。
Pumped at approximately twice the natural frequency, a Josephson parametric oscillator called parametron or Kerr parametric oscillator shows self-oscillation. Quantum annealing and universal quantum computation using self-oscillating parametrons as qubits were proposed. However, controls of parametrons under the pump field are degraded by unwanted rapidly oscillating terms in the Hamiltonian, which we call non-resonant rapidly oscillating terms (NROTs) coming from the violation of the rotating wave approximation. Therefore, the pump field can be an intrinsic origin of the imperfection of controls of parametrons. Here, we theoretically study the influence of the NROTs on the accuracy of controls of a parametron: a cat-state creation and a single-qubit gate. It is shown that there is a trade-off relationship between the suppression of the nonadiabatic transitions and the validity of the rotating wave approximation in a conventional approach. We also show that the tailored time dependence of the detuning of the pump field can suppress both of the nonadiabatic transitions and the disturbance of the state of the parametron due to the NROTs.
