Scappucci, Giordano; Kloeffel, Christoph; Zwanenburg, Floris A.; Loss, Daniel; Myronov, Maksym; Zhang, Jian-Jun; Franceschi, Silvano De; Katsaros, GeorgiosISTA; Veldhorst, Menno
In the worldwide endeavor for disruptive quantum technologies, germanium is emerging as a versatile material to realize devices capable of encoding, processing, or transmitting quantum information. These devices leverage special properties of the germanium valence-band states, commonly known as holes, such as their inherently strong spin-orbit coupling and the ability to host superconducting pairing correlations. In this Review, we initially introduce the physics of holes in low-dimensional germanium structures with key insights from a theoretical perspective. We then examine the material science progress underpinning germanium-based planar heterostructures and nanowires. We review the most significant experimental results demonstrating key building blocks for quantum technology, such as an electrically driven universal quantum gate set with spin qubits in quantum dots and superconductor-semiconductor devices for hybrid quantum systems. We conclude by identifying the most promising prospects toward scalable quantum information processing.
Nature Reviews Materials
G.S., M.W.,F.A.Z acknowledge financial support from The Netherlands Organization for Scientific Research (NWO). F.Z., D.L., G.K. acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under Grand Agreement Nr. 862046. G.K. acknowledges funding from FP7 ERC Starting Grant 335497, FWF Y 715-N30, FWF P-30207. S.D. acknowledges support from the European Union’s Horizon 2020 program under Grant Agreement No. 81050 and from the Agence Nationale de la Recherche through the TOPONANO and CMOSQSPIN projects. J.Z. acknowledges support from the National Key R&D Program of China (Grant No. 2016YFA0301701) and Strategic Priority Research Program of CAS (Grant No. XDB30000000). D.L. and C.K. acknowledge the Swiss National Science Foundation and NCCR QSIT.
Scappucci G, Kloeffel C, Zwanenburg FA, et al. The germanium quantum information route. Nature Reviews Materials. 2020;6:926–943. doi:10.1038/s41578-020-00262-z
Scappucci, G., Kloeffel, C., Zwanenburg, F. A., Loss, D., Myronov, M., Zhang, J.-J., … Veldhorst, M. (2020). The germanium quantum information route. Nature Reviews Materials. Springer Nature. https://doi.org/10.1038/s41578-020-00262-z
Scappucci, Giordano, Christoph Kloeffel, Floris A. Zwanenburg, Daniel Loss, Maksym Myronov, Jian-Jun Zhang, Silvano De Franceschi, Georgios Katsaros, and Menno Veldhorst. “The Germanium Quantum Information Route.” Nature Reviews Materials. Springer Nature, 2020. https://doi.org/10.1038/s41578-020-00262-z.
G. Scappucci et al., “The germanium quantum information route,” Nature Reviews Materials, vol. 6. Springer Nature, pp. 926–943, 2020.
Scappucci G, Kloeffel C, Zwanenburg FA, Loss D, Myronov M, Zhang J-J, Franceschi SD, Katsaros G, Veldhorst M. 2020. The germanium quantum information route. Nature Reviews Materials. 6, 926–943.
Scappucci, Giordano, et al. “The Germanium Quantum Information Route.” Nature Reviews Materials, vol. 6, Springer Nature, 2020, pp. 926–943, doi:10.1038/s41578-020-00262-z.