Quantum control of spin qubits using nanomagnets
Quantum control of spin qubits using nanomagnets
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DOI：
10.1038/s42005-022-01041-8
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发表时间：
2022-03
影响因子：
5.5
通讯作者：
Mohamad Niknam;M. F. Chowdhury;M. Rajib;W. A. Misba;R. Schwartz;Kang L. Wang;J. Atulasimha;L. Bouc
中科院分区：
文献类型：
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作者：
Mohamad Niknam;M. F. Chowdhury;M. Rajib;W. A. Misba;R. Schwartz;Kang L. Wang;J. Atulasimha;L. Bouc
单量子比特门是通用量子计算机的重要组成部分。如果没有对单个量子比特的选择性寻址，量子算法的可扩展实现是极具挑战性的。当量子位是晶格上的离散点或区域时，由于难以将经典无发散场定位和限制在小体积的空间中，因此在纳米级选择性地寻址磁性自旋量子位仍然是一个挑战。在这里，我们提出了一种技术，用于寻址自旋量子位使用电压控制的纳米磁性，举例说明了使用电压控制的磁各向异性。我们表明，通过调整纳米磁体的电场驱动的频率的拉莫尔频率的自旋限制在一个纳米尺度的体积，并通过调制的驱动器的相位，单量子比特量子门与接近的容错量子计算的quantiities可以实现。这种单量子位门操作只需要几十个毫微微焦耳，并且具有无损的纯磁场控制。它们的物理实现也是直接使用铸造制造技术。
Single-qubit gates are essential components of a universal quantum computer. Without selective addressing of individual qubits, scalable implementation of quantum algorithms is extremely challenging. When the qubits are discrete points or regions on a lattice, selectively addressing magnetic spin qubits at the nanoscale remains a challenge due to the difficulty of localizing and confining a classical divergence-free field to a small volume of space. Herein we propose a technique for addressing spin qubits using voltage-control of nanoscale magnetism, exemplified by the use of voltage control of magnetic anisotropy. We show that by tuning the frequency of the nanomagnet’s electric field drive to the Larmor frequency of the spins confined to a nanoscale volume, and by modulating the phase of the drive, single-qubit quantum gates with fidelities approaching those for fault-tolerant quantum computing can be implemented. Such single-qubit gate operations require only tens of femto-Joules per gate operation and have lossless, purely magnetic field control. Their physical realization is also straightforward using foundry manufacturing techniques.