Quantum dot arrays in silicon and germanium
Quantum dot arrays in silicon and germanium
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DOI：
10.1063/5.0002013
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发表时间：
2020-02-24
影响因子：
4
通讯作者：
Veldhorst, M.
中科院分区：
文献类型：
--
作者：
Lawrie, W. I. L.;Eenink, H. G. J.;Veldhorst, M.
限制在量子点中的电子和空穴定义了量子出现、模拟和计算的优秀构建模块。硅和锗与标准半导体制造兼容，并且含有具有零核自旋的稳定同位素，从而作为具有长量子相干性的自旋的优良宿主。在这里，我们展示了硅金属氧化物半导体（SiMOS），应变硅（Si/SiGe），应变锗（Ge/SiGe）中的量子点阵列。我们制造使用多层技术来实现紧密限制的量子点和比较集成过程。虽然SiMOS可以受益于更大的温度预算，并且Ge/SiGe可以与金属形成欧姆接触，但是用于限定量子点的重叠栅极结构可以基于几乎相同的集成。我们在每个平台上首次实现了Ge/SiGe的电荷传感，并展示了功能齐全的线性和二维阵列，其中所有量子点都可以耗尽到最后的电荷状态。在Si/SiGe中，我们使用N+1方法调谐五重量子点，以同时达到每个量子点的少电子区。我们比较电容串扰，并发现它是最小的SiMOS，相关的量子点阵列的调谐。我们将这些结果置于量子技术的角度，并将工业量子位、混合技术、自动调谐和二维量子位阵列确定为四个关键轨迹，当它们结合在一起时，可以实现容错量子计算。
Electrons and holes confined in quantum dots define excellent building blocks for quantum emergence, simulation, and computation. Silicon and germanium are compatible with standard semiconductor manufacturing and contain stable isotopes with zero nuclear spin, thereby serving as excellent hosts for spins with long quantum coherence. Here, we demonstrate quantum dot arrays in a silicon metal-oxide-semiconductor (SiMOS), strained silicon (Si/SiGe), and strained germanium (Ge/SiGe). We fabricate using a multi-layer technique to achieve tightly confined quantum dots and compare integration processes. While SiMOS can benefit from a larger temperature budget and Ge/SiGe can make an Ohmic contact to metals, the overlapping gate structure to define the quantum dots can be based on a nearly identical integration. We realize charge sensing in each platform, for the first time in Ge/SiGe, and demonstrate fully functional linear and two-dimensional arrays where all quantum dots can be depleted to the last charge state. In Si/SiGe, we tune a quintuple quantum dot using the N+1 method to simultaneously reach the few electron regime for each quantum dot. We compare capacitive crosstalk and find it to be the smallest in SiMOS, relevant for the tuning of quantum dot arrays. We put these results into perspective for quantum technology and identify industrial qubits, hybrid technology, automated tuning, and two-dimensional qubit arrays as four key trajectories that, when combined, enable fault-tolerant quantum computation.