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Badawy G, Bakkers EPAM. Electronic Transport and Quantum Phenomena in Nanowires. Chem Rev 2024; 124:2419-2440. [PMID: 38394689 PMCID: PMC10941195 DOI: 10.1021/acs.chemrev.3c00656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 01/26/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024]
Abstract
Nanowires are natural one-dimensional channels and offer new opportunities for advanced electronic quantum transport experiments. We review recent progress on the synthesis of nanowires and methods for the fabrication of hybrid semiconductor/superconductor systems. We discuss methods to characterize their electronic properties in the context of possible future applications such as topological and spin qubits. We focus on group III-V (InAs and InSb) and group IV (Ge/Si) semiconductors, since these are the most developed, and give an outlook on other potential materials.
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Affiliation(s)
- Ghada Badawy
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Erik P. A. M. Bakkers
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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2
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Kumar P, Kim H, Tripathy S, Watanabe K, Taniguchi T, Novoselov KS, Kotekar-Patil D. Excited state spectroscopy and spin splitting in single layer MoS 2 quantum dots. NANOSCALE 2023; 15:18203-18211. [PMID: 37920920 DOI: 10.1039/d3nr03844k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Semiconducting transition metal dichalcogenides (TMDCs) are very promising materials for quantum dots and spin-qubit implementation. Reliable operation of spin qubits requires the knowledge of the Landé g-factor, which can be measured by exploiting the discrete energy spectrum on a quantum dot. However, the quantum dots realized in TMDCs are yet to reach the required control and quality for reliable measurement of excited state spectroscopy and the g-factor, particularly in atomically thin layers. Quantum dot sizes reported in TMDCs so far are not small enough to observe discrete energy levels on them. Here, we report on electron transport through discrete energy levels of quantum dots in a single layer MoS2 isolated from its environment using a dual gate geometry. The quantum dot energy levels are separated by a few (5-6) meV such that the ground state and the first excited state transitions are clearly visible, thanks to the low contact resistance of ∼700 Ω and relatively low gate voltages. This well-resolved energy separation allowed us to accurately measure the ground state g-factor of ∼5 in MoS2 quantum dots. We observed a spin-filling sequence in our quantum dots under a perpendicular magnetic field. Such a system offers an excellent testbed to measure the key parameters for evaluation and implementation of spin-valley qubits in TMDCs, thus accelerating the development of quantum systems in two-dimensional semiconducting TMDCs.
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Affiliation(s)
- P Kumar
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, 119077, Singapore
| | - H Kim
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis way, Singapore 138634, Singapore.
| | - S Tripathy
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis way, Singapore 138634, Singapore.
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials, Science, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- Research Center for Functional Materials, National Institute for Materials, Science, Tsukuba, 305-0044, Japan
| | - K S Novoselov
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, 119077, Singapore
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore.
| | - D Kotekar-Patil
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, 2 Fusionopolis way, Singapore 138634, Singapore.
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Sistani M, Delaforce J, Kramer RBG, Roch N, Luong MA, den Hertog MI, Robin E, Smoliner J, Yao J, Lieber CM, Naud C, Lugstein A, Buisson O. Highly Transparent Contacts to the 1D Hole Gas in Ultrascaled Ge/Si Core/Shell Nanowires. ACS NANO 2019; 13:14145-14151. [PMID: 31816231 DOI: 10.1021/acsnano.9b06809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Semiconductor-superconductor hybrid systems have outstanding potential for emerging high-performance nanoelectronics and quantum devices. However, critical to their successful application is the fabrication of high-quality and reproducible semiconductor-superconductor interfaces. Here, we realize and measure axial Al-Ge-Al nanowire heterostructures with atomically precise interfaces, enwrapped by an ultrathin epitaxial Si layer further denoted as Al-Ge/Si-Al nanowire heterostructures. The heterostructures were synthesized by a thermally induced exchange reaction of single-crystalline Ge/Si core/shell nanowires and lithographically defined Al contact pads. Applying this heterostructure formation scheme enables self-aligned quasi one-dimensional crystalline Al leads contacting ultrascaled Ge/Si segments with contact transparencies greater than 96%. Integration into back-gated field-effect devices and continuous scaling beyond lithographic limitations allows us to exploit the full potential of the highly transparent contacts to the 1D hole gas at the Ge-Si interface. This leads to the observation of ballistic transport as well as quantum confinement effects up to temperatures of 150 K. Low-temperature measurements reveal proximity-induced superconductivity in the Ge/Si core/shell nanowires. The realization of a Josephson field-effect transistor allows us to study the subgap structure caused by multiple Andreev reflections. Most importantly, the absence of a quantum dot regime indicates a hard superconducting gap originating from the highly transparent contacts to the 1D hole gas, which is potentially interesting for the study of Majorana zero modes. Moreover, underlining the importance of the proposed thermally induced Al-Ge/Si-Al heterostructure formation technique, our system could contribute to the development of key components of quantum computing such as gatemon or transmon qubits.
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Affiliation(s)
- Masiar Sistani
- Institute of Solid State Electronics, TU Wien , Gußhausstraße 25-25a , 1040 Vienna , Austria
| | - Jovian Delaforce
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Roman B G Kramer
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Nicolas Roch
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Minh Anh Luong
- Université Grenoble Alpes, CEA, IRIG-DEPHY , F-38054 Grenoble , France
| | - Martien I den Hertog
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Eric Robin
- Université Grenoble Alpes, CEA, IRIG-DEPHY , F-38054 Grenoble , France
| | - Jürgen Smoliner
- Institute of Solid State Electronics, TU Wien , Gußhausstraße 25-25a , 1040 Vienna , Austria
| | - Jun Yao
- Department of Electrical and Computer Engineering, Institute for Applied Life Sciences , University of Massachusetts , Amherst , Massachusetts 01003 , United States
| | - Charles M Lieber
- Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , United States
- School of Engineering and Applied Science , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Cecile Naud
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
| | - Alois Lugstein
- Institute of Solid State Electronics, TU Wien , Gußhausstraße 25-25a , 1040 Vienna , Austria
| | - Olivier Buisson
- Université Grenoble Alpes, CNRS, Institut NEEL UPR2940 , F-38054 Grenoble , France
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Carrier control in 2D transition metal dichalcogenides with Al 2O 3 dielectric. Sci Rep 2019; 9:8769. [PMID: 31217503 PMCID: PMC6584693 DOI: 10.1038/s41598-019-45392-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/05/2019] [Indexed: 11/28/2022] Open
Abstract
We report transport measurements of dual gated MoS2 and WSe2 devices using atomic layer deposition grown Al2O3 as gate dielectrics. We are able to achieve current pinch-off using independent split gates and observe current steps suggesting possible carrier confinement. We also investigated the impact of gate geometry and used electrostatic potential simulations to explain the observed device physics.
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Ridderbos J, Brauns M, Shen J, de Vries FK, Li A, Bakkers EPAM, Brinkman A, Zwanenburg FA. Josephson Effect in a Few-Hole Quantum Dot. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802257. [PMID: 30260519 DOI: 10.1002/adma.201802257] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/11/2018] [Indexed: 06/08/2023]
Abstract
A Ge-Si core-shell nanowire is used to realize a Josephson field-effect transistor with highly transparent contacts to superconducting leads. By changing the electric field, access to two distinct regimes, not combined before in a single device, is gained: in the accumulation mode the device is highly transparent and the supercurrent is carried by multiple subbands, while near depletion, the supercurrent is carried by single-particle levels of a strongly coupled quantum dot operating in the few-hole regime. These results establish Ge-Si nanowires as an important platform for hybrid superconductor-semiconductor physics and Majorana fermions.
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Affiliation(s)
- Joost Ridderbos
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Matthias Brauns
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Jie Shen
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - Folkert K de Vries
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - Ang Li
- Department of Applied Physics, Eindhoven University of Technology, Postbox 513, 5600 MB, Eindhoven, The Netherlands
| | - Erik P A M Bakkers
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
- Department of Applied Physics, Eindhoven University of Technology, Postbox 513, 5600 MB, Eindhoven, The Netherlands
| | - Alexander Brinkman
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Floris A Zwanenburg
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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Mizokuchi R, Maurand R, Vigneau F, Myronov M, De Franceschi S. Ballistic One-Dimensional Holes with Strong g-Factor Anisotropy in Germanium. NANO LETTERS 2018; 18:4861-4865. [PMID: 29995419 DOI: 10.1021/acs.nanolett.8b01457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report experimental evidence of ballistic hole transport in one-dimensional quantum wires gate-defined in a strained SiGe/Ge/SiGe quantum well. At zero magnetic field, we observe conductance plateaus at integer multiples of 2 e2/ h. At finite magnetic field, the splitting of these plateaus by Zeeman effect reveals largely anisotropic g-factors with absolute values below 1 in the quantum-well plane, and exceeding 10 out-of-plane. This g-factor anisotropy is consistent with a heavy-hole character of the propagating valence-band states, which is in line with a predominant confinement in the growth direction. Remarkably, we observe quantized ballistic conductance in device channels up to 600 nm long. These findings mark an important step toward the realization of novel devices for applications in quantum spintronics.
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Affiliation(s)
- R Mizokuchi
- Université Grenoble Alpes & CEA, INAC-PHELIQS , F-38000 Grenoble , France
| | - R Maurand
- Université Grenoble Alpes & CEA, INAC-PHELIQS , F-38000 Grenoble , France
| | - F Vigneau
- Université Grenoble Alpes & CEA, INAC-PHELIQS , F-38000 Grenoble , France
| | - M Myronov
- Department of Physics , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - S De Franceschi
- Université Grenoble Alpes & CEA, INAC-PHELIQS , F-38000 Grenoble , France
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