Ramanandan Santhanu Panikar, Tomić Petar, Morgan Nicholas Paul, Giunto Andrea, Rudra Alok, Ensslin Klaus, Ihn Thomas, Fontcuberta I Morral Anna
Laboratory of Semiconductor Materials, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne 1015, Switzerland.
Solid State Laboratory, ETH Zurich, 8093 Zurich, Switzerland.
Nano Lett. 2022 May 25;22(10):4269-4275. doi: 10.1021/acs.nanolett.2c00358. Epub 2022 May 4.
Holes in germanium nanowires have emerged as a realistic platform for quantum computing based on spin qubit logic. On top of the large spin-orbit coupling that allows fast qubit operation, nanowire geometry and orientation can be tuned to cancel out charge noise and hyperfine interaction. Here, we demonstrate a scalable approach to synthesize and organize Ge nanowires on silicon (100)-oriented substrates. Germanium nanowire networks are obtained by selectively growing on nanopatterned slits in a metalorganic vapor phase epitaxy system. Low-temperature electronic transport measurements are performed on nanowire Hall bar devices revealing high hole doping of ∼10 cm and mean free path of ∼10 nm. Quantum diffusive transport phenomena, universal conductance fluctuations, and weak antilocalization are revealed through magneto transport measurements yielding a coherence and a spin-orbit length of the order of 100 and 10 nm, respectively.
基于自旋量子比特逻辑的量子计算中，锗纳米线中的空穴已成为一个切实可行的平台。除了具备能实现快速量子比特操作的大自旋轨道耦合外，纳米线的几何形状和取向还可进行调整，以抵消电荷噪声和超精细相互作用。在此，我们展示了一种可扩展的方法，用于在硅（100）取向衬底上合成和组织锗纳米线。通过在金属有机气相外延系统中的纳米图案化狭缝上选择性生长，可获得锗纳米线网络。在纳米线霍尔条形器件上进行了低温电子输运测量，结果显示空穴掺杂浓度约为10 cm ，平均自由程约为10 nm。通过磁输运测量揭示了量子扩散输运现象、普遍电导涨落和弱反局域化，其相干长度和自旋轨道长度分别约为100 nm和10 nm。
