Top-down pathways to devices with few and single atoms placed to high precision
Top-down pathways to devices with few and single atoms placed to high precision
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DOI：
10.1088/1367-2630/12/6/065016
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发表时间：
2010-06
影响因子：
3.3
通讯作者：
J. V. Van Donkelaar;A. Greentree;A. Alves;L. M. Jong;L. Hollenberg;D. Jamieson
中科院分区：
文献类型：
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作者：
J. V. Van Donkelaar;A. Greentree;A. Alves;L. M. Jong;L. Hollenberg;D. Jamieson
由于经典微电子学的技术进步，以及基于自旋或电荷的量子计算机的提议，使用很少单个原子的固态设备正在出现。在这两个领域制造器件都需要开发确定的硅掺杂技术，在这种技术中，必须将很少或单一的掺杂原子放置到通常是纳米级的精度。在这里，我们讨论了一种基于确定性离子注入的自上而下的方法，该方法可能被用来制造器件，旨在探索在单原子极限下设计、制造和测量固态器件的新挑战。特别是，我们讨论了制造更复杂的利用量子相干的设备的潜力。我们提出了一种用于可扩展量子计算机的三施主原型器件，它通过绝热通道相干隧穿(CTAP)协议传输电子自旋量子比特。我们通过在类氢假设下对CTAP输运性质的解析处理，从理论上检验了离子注入掺杂放置的统计特性。我们评估了在离子注入的限制下制造概念验证器件的可能性。我们发现，对于靶原子位间距为30 nm的14keV磷注入硅，结果是有希望的，产额为六分之一，对于低能量注入，可能有更高的产额。这表明确定性掺杂是制备和测试近期实用量子相干器件的重要工具。
Solid-state devices that employ few and single atoms are emerging as a consequence of technological advances in classical microelectronics and proposals for quantum computers based on spin or charge. The fabrication of devices in both these areas requires the development of techniques for deterministic doping of silicon where few or single dopant atoms must be placed to, typically, nanometre precision. Here we discuss a top-down approach, based on deterministic ion implantation, which can potentially be used to fabricate devices intended to explore the novel challenges of designing, building and measuring solid-state devices at the single atom limit. In particular, we address the potential of fabricating more complex devices that exploit quantum coherence. We propose a prototype triple-donor device that transports electron spin qubits via the coherent tunnelling by adiabatic passage (CTAP) protocol for a scalable quantum computer. We examine theoretically the statistics of dopant placement using ion implantation by employing an analytical treatment of CTAP transport properties under hydrogenic assumptions. We evaluate the probability of fabricating proof of concept devices subject to the limitations of ion implantation. We find that the results are promising with a yield of one in six for 14 keV phosphorus implanted into silicon with a target atom site spacing of 30 nm with even higher yields possible for lower-energy implants. This suggests that deterministic doping is an important tool to fabricate and test near-term practical quantum coherent devices.