论文标题
使用条件驱动的两分闸门用于高度失调的Kerr-Nonlinear参数振荡器
Two-qubit gate using conditional driving for highly detuned Kerr-nonlinear parametric oscillators
论文作者
论文摘要
Kerr-Nonilinear参数振荡器（KPO）是实现通用量子计算量子位的有前途的设备之一。 KPO可以以相反的相位稳定两个连贯的状态，从而产生称为schrödinger猫状态的量子叠加。使用KPO的通用量子计算需要三种量子门：$ r_z，r_x $和$ r_ {zz} $门。从理论上讲，我们为高度失调的kpos提出了两个Qubit Gate $ R_ {ZZ} $。在拟议的方案中，我们为第一个KPO添加了另一个两光驱动器。这导致$ r_ {zz} $ gate基于第二个kpo的驾驶，具体取决于第一个kpo状态，我们称之为“有条件驾驶”。首先，我们使用在某些近似值下源自超导电路模型的常规KPO Hamiltonian进行仿真，并评估栅极的保真度。接下来，我们还使用无近似值的超导电路模型对两数Qubit门进行了数值模拟。模拟结果表明，可以用高保真（$> 99.9 \％$）实现两倍的门，以实现通用性所需的旋转角度。
A Kerr-nonlinear parametric oscillator (KPO) is one of the promising devices to realize qubits for universal quantum computing. The KPO can stabilize two coherent states with opposite phases, yielding a quantum superposition called a Schrödinger cat state. Universal quantum computing with KPOs requires three kinds of quantum gates: $R_z, R_x$, and $R_{zz}$ gates. We theoretically propose a two-qubit gate $R_{zz}$ for highly detuned KPOs. In the proposed scheme, we add another two-photon drive for the first KPO. This leads to the $R_{zz}$ gate based on the driving of the second KPO depending on the first-KPO state, which we call "conditional driving." First, we perform simulations using a conventional KPO Hamiltonian derived from a superconducting-circuit model under some approximations and evaluate the gate fidelity. Next, we also perform numerical simulations of the two-qubit gate using the superconducting-circuit model without the approximations. The simulation results indicate that two-qubit gates can be implemented with high fidelity ($>99.9\%$) for rotation angles required for universality.
