论文标题
2D双层中的范德华电荷值：从头量量子运输和量子测量
Dynamics of van der Waals Charge Qubit in 2D Bilayers: Ab initio Quantum Transport and Qubit Measurement
论文作者
论文摘要
范德华（VDW）电荷量子置量固定在二维（2D）VDW材料中，被提议作为未来量子计算机的构建块。它的特征是根据其两级反跨能量差（$δ$）系统评估的。双层石墨烯（$δ$ \ \ $ \ $ 0）和VDW异质结构（$δ$ $ \ gg $ 0）用作代表性示例。它们具有外部电场的可调电子性能定义了电荷值的状态。通过结合密度功能理论和量子传输计算，我们根据电荷稳定性和能量级图强调了最佳的量子运行条件。此外，将基于三层VDW异质结构的单电体晶体管（SET）设计与电荷量轴耦合在一起，作为具有低脱干性和改进的测量属性的测量设置。发现大于20 meV的$δ$导致量子状态的快速混合，从而导致测量量较低，即对比度和电导率。通过正确优化的设计，依靠2D VDW结构的量子体系结构可以集成到全电子量子计算平台中。
A van der Waals (vdW) charge qubit, electrostatically confined within two-dimensional (2D) vdW materials, is proposed as building block of future quantum computers. Its characteristics are systematically evaluated with respect to its two-level anti-crossing energy difference ($Δ$). Bilayer graphene ($Δ$ $\approx$ 0) and a vdW heterostructure ($Δ$ $\gg$ 0) are used as representative examples. Their tunable electronic properties with an external electric field define the state of the charge qubit. By combining density functional theory and quantum transport calculations, we highlight the optimal qubit operation conditions based on charge stability and energy-level diagrams. Moreover, a single-electron transistor (SET) design based on trilayer vdW heterostructures capacitively coupled to the charge qubit is introduced as measurement setup with low decoherence and improved measurement properties. It is found that a $Δ$ greater than 20 meV results in a rapid mixing of the qubit states, which leads to a lower measurement quantity, i.e. contrast and conductance. With properly optimized designs, qubit architectures relying on 2D vdW structures could be integrated into an all-electronic quantum computing platform.
