Constructing clock-transition-based two-qubit gates from dimers of molecular nanomagnets
Constructing clock-transition-based two-qubit gates from dimers of molecular nanomagnets
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DOI：
10.1103/physrevresearch.2.032037
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发表时间：
2020-08-13
影响因子：
4.2
通讯作者：
Friedman, Jonathan R.
中科院分区：
文献类型：
--
作者：
Collett, Charles A.;Santini, Paolo;Friedman, Jonathan R.
一个好的量子位必须有足够长的相干时间来执行门操作。避免的电平交叉允许时钟转换，其中通过转换对外部场中的波动的不敏感性来增强相干性。由于这种不敏感性，如何在保持时钟转换行为的同时有效地将量子位耦合在一起并不明显。在这里，我们提出了一个使用两个耦合分子纳米磁体的异二聚体的方案，每个纳米磁体在零磁场下具有时钟跃迁，其中实现一个和两个量子位门所需的所有门操作可以用脉冲射频辐射来实现。我们表明，在二聚体中的纳米磁体之间的现实耦合强度，可以实现良好的栅极结晶度（类似于99.4%）。我们确定了实现门的主要错误来源，并讨论了如何减轻这些错误，并调查了这样一个系统成为实现量子计算协议的可行平台所需的相干时间范围。
A good qubit must have a coherence time long enough for gate operations to be performed. Avoided level crossings allow for clock transitions in which coherence is enhanced by the insensitivity of the transition to fluctuations in external fields. Because of this insensitivity, it is not obvious how to effectively couple qubits together while retaining clock-transition behavior. Here we present a scheme for using a heterodimer of two coupled molecular nanomagnets, each with a clock transition at zero magnetic field, in which all of the gate operations needed to implement one- and two-qubit gates can be implemented with pulsed radio-frequency radiation. We show that given realistic coupling strengths between the nanomagnets in the dimer, good gate fidelities (similar to 99.4%) can be achieved. We identify the primary sources of error in implementing gates and discuss how these may be mitigated, and investigate the range of coherence times necessary for such a system to be a viable platform for implementing quantum computing protocols.