Designing Kerr interactions using multiple superconducting qubit types in a single circuit
Designing Kerr interactions using multiple superconducting qubit types in a single circuit
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DOI：
10.1088/1367-2630/aa9243
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发表时间：
2017-09
影响因子：
3.3
通讯作者：
M. Elliott;J. Joo;E. Ginossar
中科院分区：
文献类型：
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作者：
M. Elliott;J. Joo;E. Ginossar
克尔相互作用的工程对于处理多体量子系统中的量子信息和研究复杂腔量子比特网络中的多体物理具有极大的兴趣。我们研究了如何将多个不同类型的超导量子位耦合到相同的腔模，以修改作用于腔的自克尔效应和交叉克尔效应，并证明这种类型的架构可能对量子技术有重大意义。使用解析微扰理论的结果和数值模拟，我们首先表明，耦合两个超导量子比特具有相反的非谐性到一个单一的腔，使有效的自克尔相互作用被削弱，同时保留的数量分裂效应，使控制和测量的腔场。我们证明，这种减少的自克尔效应可以保持的保真度的相干态和广义薛定谔猫态的时间远长于典型的相干时间在现实的设备。接下来，我们发现两个腔之间的交叉克尔相互作用可以通过将它们耦合到同一对量子比特设备来修改。当其中一个量子比特的频率可调时，腔之间的纠缠相互作用的强度可以根据需要变化，从而形成两种模式的逻辑运算的基础。最后，我们讨论了产生腔和量子位阵列的可行性，其中中间和现场量子位可以调整整个系统中自相互作用和交叉克尔相互作用的强度。这种结构可以提供一种方法来设计有趣的多体哈密顿量，并为电路量子电动力学的量子模拟提供一个有用的平台。
The engineering of Kerr interactions is of great interest for processing quantum information in multipartite quantum systems and for investigating many-body physics in a complex cavity-qubit network. We study how coupling multiple different types of superconducting qubits to the same cavity modes can be used to modify the self- and cross-Kerr effects acting on the cavities and demonstrate that this type of architecture could be of significant benefit for quantum technologies. Using both analytical perturbation theory results and numerical simulations, we first show that coupling two superconducting qubits with opposite anharmonicities to a single cavity enables the effective self-Kerr interaction to be diminished, while retaining the number splitting effect that enables control and measurement of the cavity field. We demonstrate that this reduction of the self-Kerr effect can maintain the fidelity of coherent states and generalised Schrödinger cat states for much longer than typical coherence times in realistic devices. Next, we find that the cross-Kerr interaction between two cavities can be modified by coupling them both to the same pair of qubit devices. When one of the qubits is tunable in frequency, the strength of entangling interactions between the cavities can be varied on demand, forming the basis for logic operations on the two modes. Finally, we discuss the feasibility of producing an array of cavities and qubits where intermediary and on-site qubits can tune the strength of self- and cross-Kerr interactions across the whole system. This architecture could provide a way to engineer interesting many-body Hamiltonians and be a useful platform for quantum simulation in circuit quantum electrodynamics.