论文标题
在超导Qutrit中实施WALSH-HADAMARD门
Implementation of a Walsh-Hadamard gate in a superconducting qutrit
论文作者
论文摘要
我们已经在超导Qutrit中实现了一个walsh-Hadamard门，该沃尔什 - 哈达玛栅门在Qutrit中执行量子傅立叶变换。 QUTRIT在电容分流的通量设备的最低三个能级中编码，该通量设备在最佳通量对称点处运行。我们将Walsh-Hadamard门有效地分解为两个单位，分别由异位和对角线汉密尔顿人产生。门实现利用了QUTRIT的三对能级之间的所有三个过渡的同时驾驶，其中之一是通过两光孔过程实现的。该门的持续时间为35 ns，在一组代表性状态下的平均保真度，包括制备和层析成像误差为99.2％，其特征是量子状态层析成像。 AC-Stark和Bloch-Siegert Shifts的补偿对于达到高门的保真度至关重要。
We have implemented a Walsh-Hadamard gate, which performs a quantum Fourier transform, in a superconducting qutrit. The qutrit is encoded in the lowest three energy levels of a capacitively shunted flux device, operated at the optimal flux-symmetry point. We use an efficient decomposition of the Walsh-Hadamard gate into two unitaries, generated by off-diagonal and diagonal Hamiltonians respectively. The gate implementation utilizes simultaneous driving of all three transitions between the three pairs of energy levels of the qutrit, one of which is implemented with a two-photon process. The gate has a duration of 35 ns and an average fidelity over a representative set of states, including preparation and tomography errors, of 99.2%, characterized with quantum state tomography. Compensation of ac-Stark and Bloch-Siegert shifts is essential for reaching high gate fidelities.
