EMT/QIS: Quantum Control of Impurity States in a Semiconductor

半导体中杂质态的量子控制。兰辛，MI 48824摘要量子信息是一个新的和迅速发展的跨学科的研究领域，驻留在量子物理和信息科学之间的接口。它解决了科学和技术中一些最具挑战性的基本问题，同时寻求推进我们对量子世界独特性质的理解。在这一领域的预测中，有一个是纯粹基于量子原理的计算机的指数加速。如果要利用量子特性开发新的定性能力，就必须建立具有长寿命、可控量子态的系统。此外，这些设备应该与传统的电子学和光子学兼容。基于半导体中受控杂质态的器件特别有吸引力，因为它们应该是可扩展的，高速运行，并利用现有的半导体技术。在实验和理论研究中研究的量子系统是基于半导体中的受体，如硅。这些都是替代掺杂剂，其原子性质是众所周知的和不变的。一个量子比特的两个状态是受体的最低轨道状态，是基态被应变和电场分裂的结果。能级之间的距离在几GHz的范围内，并且每个量子比特由栅电极单独控制。单量子比特操作可以用短的微波脉冲来实现，而两个量子比特操作则可以通过受体之间的长程偶极相互作用来实现，这使得量子比特之间的距离超过100 nm。系统最终状态的读出是基于量子非破坏光学测量的光散射的激子绑定到受体。

Quantum Control of Impurity States in a SemiconductorBrage Golding and Mark DykmanMichigan State UniversityE. Lansing, MI 48824ABSTRACTQuantum information is a new and rapidly developing interdisciplinary area of researchthat resides at the interface between quantum physics and information science. Itaddresses some of the most challenging fundamental problems in science and technologywhile seeking to advance our understanding of the unique properties of the quantumworld. Among the predictions in this field is that of an exponential speedup of computersthat operate on purely quantum principles. If quantum properties are to be exploited forqualitatively new capabilities, it is necessary to build systems that exhibit long-lived,controllable quantum states. In addition, the devices should be compatible withconventional electronics and photonics. The devices based on controlled impurity statesin semiconductors stand out as particularly attractive, since they should be scalable,operate at high speed, and take advantage of existing semiconductor technology.The quantum systems studied in this experimental and theoretical research are based onacceptors in a semiconductor such as silicon. These are substitutional dopants, whoseatomic-like properties are well-known and invariant. The two states of a qubit are thelowest orbital states of the acceptor, a result of splitting of the ground state by strain andelectric field. The distance between the energy levels is in the range of a few GHz andeach qubit is individually controlled by a gate electrode. Single-qubit operations can beperformed with short microwave pulses whereas two-qubit operations are enabled by thelong-range dipolar interaction between the acceptors, which allows the qubit-qubitdistance to be more than 100 nm. The readout of the final state of the system is based onquantum nondemolition optical measurement of light scattering by an exciton bound tothe acceptor.