Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology, University of New South Wales, Sydney, New South Wales 2052, Australia.
Nat Commun. 2013;4:2017. doi: 10.1038/ncomms3017.
The spin states of an electron bound to a single phosphorus donor in silicon show remarkably long coherence and relaxation times, which makes them promising building blocks for the realization of a solid-state quantum computer. Here we demonstrate, by high-fidelity (93%) electrical spin readout, that a long relaxation time T1 of about 2 s, at B=1.2 T and T≈100 mK, is also characteristic of electronic spin states associated with a cluster of few phosphorus donors, suggesting their suitability as hosts for spin qubits. Owing to the difference in the hyperfine coupling, electronic spin transitions of such clusters can be sufficiently distinct from those of a single phosphorus donor. Our atomistic tight-binding calculations reveal that when neighbouring qubits are hosted by a single phosphorus atom and a cluster of two phosphorus donors, the difference in their electron spin resonance frequencies allows qubit rotations with error rates ≈10(-4). These results provide a new approach to achieving individual qubit addressability.
束缚在硅中单磷原子上的电子的自旋态表现出显著的长相干和弛豫时间，这使得它们成为实现固态量子计算机的有前途的构建块。在这里，我们通过高保真度（93%）的电自旋读出证明，在 B=1.2 T 和 T≈100 mK 时，弛豫时间 T1 也约为 2 s，与少数磷原子供体簇相关的电子自旋态具有特征，这表明它们适合作为自旋量子位的宿主。由于超精细耦合的差异，这样的簇的电子自旋跃迁可以与单个磷原子供体的跃迁充分区分开来。我们的原子紧束缚计算表明，当相邻的量子位由单个磷原子和两个磷原子供体簇来承载时，它们的电子自旋共振频率的差异允许以 ≈10(-4)的错误率进行量子位旋转。这些结果为实现单个量子位可寻址性提供了一种新方法。
