Optically Controlled Spin Gate Using GaN Quantum Dots
Optically Controlled Spin Gate Using GaN Quantum Dots
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DOI：
10.1021/acsphotonics.2c00083
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发表时间：
2022-04
期刊：
影响因子：
7
通讯作者：
Juhyeon Kim;Zachary Croft;D. Steel;P. Ku
中科院分区：
文献类型：
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作者：
Juhyeon Kim;Zachary Croft;D. Steel;P. Ku
分析了两种不同半导体异质结横向放置的量子点单光子发射体。基于两个量子点三子之间的库仑相互作用，给出了两个量子点自旋之间的可控位相门。这种相互作用移动了比特子的能量流形，使得能够根据控制量子比特的状态获得π相移。门的保真度随着比特子耦合的增加而增加，这反过来又取决于量子点之间的间距。在实际应用中，这种间距需要足够大，才能制造出双量子点系统。与In(Ga)As量子点相比，体相GaN和线中点结构的In(Ga)N量子点都表现出比In(Ga)N量子点更强的比特相互作用。In(Ga)N点中增强的比特离子耦合增加了实现相同栅极性能所需的边缘到边缘点间间距，从而允许基于现场控制的线中点In(Ga)N量子点设计确定性自旋自旋门，这种量子点可以使用最先进的光刻技术轻松制造出10 nm的点间间距。
Two laterally positioned quantum dot single-photon emitters in different semiconductor heterostructures were analyzed. A controlled phase gate between two quantum dot spins was shown based on the Coulomb interaction between the two quantum dot trions. The interaction shifts the bitrion energy manifold, enabling a π-phase shift to be acquired depending on the state of the control qubit. The gate fidelity increases with an increasing bitrion coupling which in turn depends on the spacing between the quantum dots. In practical applications, this spacing needs to be sufficiently large to allow the two-quantum-dot system to be fabricated. An enhanced bitrion coupling was shown in In(Ga)N quantum dots both in a bulk GaN matrix and in a dot-in-wire geometry, compared to that in In(Ga)As dots. The enhanced bitrion coupling in In(Ga)N dots increases the edge-to-edge interdot spacing needed to achieve the same gate performance, allowing a deterministic spin–spin gate to be designed based on site-controlled dot-in-wire In(Ga)N quantum dots that can be readily fabricated with an interdot spacing of 10 nm using state-of-the-art lithography.