Print Email Facebook Twitter Shallow and undoped germanium quantum wells: A playground for spin and hybrid quantum technology Title Shallow and undoped germanium quantum wells: A playground for spin and hybrid quantum technology Author Sammak, A. Sabbagh, D. Hendrickx, N.W. Lodari, M. Paquelet Wuetz, B. Tosato, A. Yeoh, L. Bollani, M. Virgilio, M. Schubert, M.A. Zaumseil, P. Capellini, G. Veldhorst, M. Scappucci, G. Publication year 2019 Abstract Buried-channel semiconductor heterostructures are an archetype material platform for the fabrication of gated semiconductor quantum devices. Sharp confinement potential is obtained by positioning the channel near the surface; however, nearby surface states degrade the electrical properties of the starting material. Here, a 2D hole gas of high mobility (5 × 105 cm2 V−1 s−1) is demonstrated in a very shallow strained germanium (Ge) channel, which is located only 22 nm below the surface. The top-gate of a dopant-less field effect transistor controls the channel carrier density confined in an undoped Ge/SiGe heterostructure with reduced background contamination, sharp interfaces, and high uniformity. The high mobility leads to mean free paths ≈ 6 μm, setting new benchmarks for holes in shallow field effect transistors. The high mobility, along with a percolation density of 1.2 × 1011cm−2, light effective mass (0.09me), and high effective g-factor (up to 9.2) highlight the potential of undoped Ge/SiGe as a low-disorder material platform for hybrid quantum technologies. Subject High Tech Systems & MaterialsIndustrial Innovation To reference this document use: http://resolver.tudelft.nl/uuid:ded616da-2237-4cb4-bbe3-4c508f3226ca TNO identifier 875391 Publisher Wiley, Weinheim, Germany Source Advanced Functional Materials, 29 Article number 1807613 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.