Zheng Han, Cheung Luk Yi, Sangwan Nikunj, Kononov Artem, Haller Roy, Ridderbos Joost, Ciaccia Carlo, Ungerer Jann Hinnerk, Li Ang, Bakkers Erik P A M, Baumgartner Andreas, Schönenberger Christian
Quantum- and Nanoelectronics Lab, Department of Physics, University of Basel, 4056 Basel, Switzerland.
MESA+ Institute for Nanotechnology University of Twente, 7500 AE Enschede, The Netherlands.
Nano Lett. 2024 Jun 7;24(24):7173-9. doi: 10.1021/acs.nanolett.4c00770.
Gatemon qubits are the electrically tunable cousins of superconducting transmon qubits. In this work, we demonstrate the full coherent control of a gatemon qubit based on hole carriers in a Ge/Si core/shell nanowire, with the longest coherence times in group IV material gatemons to date. The key to these results is a high-quality Josephson junction obtained using a straightforward and reproducible annealing technique. We demonstrate that the transport through the narrow junction is dominated by only two quantum channels, with transparencies up to unity. This novel qubit platform holds great promise for quantum information applications, not only because it incorporates technologically relevant materials, but also because it provides new opportunities, like an ultrastrong spin-orbit coupling in the few-channel regime of Josephson junctions.
加特蒙量子比特是超导跨导量子比特的电可调谐同类物。在这项工作中，我们展示了基于锗/硅核壳纳米线中空穴载流子的加特蒙量子比特的完全相干控制，其具有迄今为止IV族材料加特蒙中最长的相干时间。这些结果的关键在于使用一种简单且可重复的退火技术获得的高质量约瑟夫森结。我们证明，通过窄结的输运仅由两个量子通道主导，透明度高达1。这个新颖的量子比特平台在量子信息应用方面具有巨大潜力，不仅因为它包含了具有技术相关性的材料，还因为它提供了新的机会，比如在约瑟夫森结的少通道 regime 中存在超强自旋轨道耦合。
