Quantum gates with donors in germanium
Quantum gates with donors in germanium
复制标题
DOI：
10.1103/physrevb.94.205309
复制
发表时间：
2016-11-29
影响因子：
3.7
通讯作者：
Lovett, Brendon W.
中科院分区：
文献类型：
--
作者：
Pica, Giuseppe;Lovett, Brendon W.
最近的研究表明，锗（Ge）纳米级晶体管中的电子自旋可以电调谐，并且具有令人鼓舞的相干时间。基于完整且经过验证的Ge给体电子态理论，我们提出Ge自旋量子比特在实现基于给体的量子处理器架构方面可能比硅（Si）具有显着优势。我们的工作表明，与Si相比，Ge带结构的固有特征允许选择性（局部）单量子比特门的加速高达两个数量级。此外，我们发现Ge中快速、健壮的双量子位门的制造限制比Si器件不那么严格：Ge供体的间距是Si器件的三倍，显示出类似的交换耦合，从而为读出和控制门提供了更多的空间。此外，对于施主位置的实际位置不确定性，Ge: P自旋耦合有33%的机会在最大耦合的一个数量级内，而Si: P的自旋耦合只有10%。因此，基于Ge的平台可能会为量子计算实现快速、并行和健壮的架构。
Recent work has shown that electron spins in germanium (Ge) nanoscale transistors can be electrically tuned and have encouraging coherence times. Based on a complete and validated theory of Ge-donor electron states, we propose that Ge spin qubits could have significant advantages over silicon (Si) in the implementation of a donor-based quantum processor architecture. Our work shows that the intrinsic features of the Ge band structure allow for a speedup of selective (local) one-qubit gates of up to two orders of magnitude as compared to Si. Further, we find that fast, robust two-qubit gates in Ge pose less stringent fabrication constraints than in Si devices: Ge donors spaced three times farther apart than in Si show comparable exchange couplings, allowing more space for readout and control gates. In addition, for realistic position uncertainty in donor placement, Ge: P spin couplings have a 33% chance of being within an order of magnitude of the largest coupling, compared with only 10% in Si: P. It is therefore possible that a Ge-based platform would enable fast, parallel, and robust architectures for quantum computing.