论文标题
KERR参数振荡器的量子状态层析成像
Quantum state tomography for Kerr parametric oscillators
论文作者
论文摘要
QED体系结构中实现的KERR参数振荡器（KPO）可以作为Qubits运行。他们对量子退火和通用量子计算的应用已经进行了深入研究。对于这些应用程序，KPO状态的读数至关重要。我们开发了针对KPO的国家断层扫描方案，并进行了反射测量。尽管众所周知，反射系数取决于KPO的状态，但尚不清楚是否可以以实用的方式进行编码为KPO的QPO的断层扫描，从而在测量过程中降低脱干性以及其准确性。我们表明，当正确选择探针频率并引入额外的单光驱动器时，反射系数与量子矩阵密度矩阵的对角线具有一对一的对应关系。因此，我们的方案提供了一种新颖的方式，可以沿Bloch球形的轴读取量子，因此反射测量和单量门门可以构成状态断层扫描。
Kerr parametric oscillators (KPOs) implemented in the circuit QED architecture can operate as qubits. Their applications to quantum annealing and universal quantum computation have been studied intensely. For these applications, the readout of the state of KPOs is of practical importance. We develop a scheme of state tomography for KPOs with reflection measurement. Although it is known that the reflection coefficient depends on the state of the KPO, it is unclear whether tomography of a qubit encoded into a KPO can be performed in a practical way mitigating decoherence during the measurement, and how accurate it is. We show that the reflection coefficient has a one-to-one correspondence with a diagonal element of the density matrix of the qubit when a probe frequency is properly chosen and an additional single-photon-drive is introduced. Thus, our scheme offers a novel way to readout the qubit along an axis of the Bloch sphere, and therefore the reflection measurement and single-qubit gates can constitute state tomography.
