Giant electron-hole transport asymmetry in ultra-short quantum transistors
| Autor: | V. Tayari, A. C. McRae, A. R. Champagne, James Porter |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Nanotube
Band gap Science General Physics and Astronomy Hardware_PERFORMANCEANDRELIABILITY 02 engineering and technology Electron hole Electron 7. Clean energy 01 natural sciences Article General Biochemistry Genetics and Molecular Biology Condensed Matter::Materials Science Computer Science::Hardware Architecture Computer Science::Emerging Technologies Hardware_GENERAL 0103 physical sciences Hardware_INTEGRATEDCIRCUITS Physics::Atomic and Molecular Clusters 010306 general physics Quantum Physics Multidisciplinary Condensed matter physics General Chemistry Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Quantum bus Carbon nanotube quantum dot Quantum dot ComputerSystemsOrganization_MISCELLANEOUS 0210 nano-technology Hardware_LOGICDESIGN |
| Zdroj: | Nature Communications Nature Communications, Vol 8, Iss 1, Pp 1-8 (2017) |
| ISSN: | 2041-1723 |
| DOI: | 10.1038/ncomms15491 |
| Popis: | Making use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e−h charging energy asymmetry). We parameterize the e−h transport asymmetry by the ratio of the hole and electron charging energies ηe−h. This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, ηe−h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV. By utilizing electron-hole asymmetry in ultra-short single-walled carbon nanotube (SWCNT) transistors, McRae et al., develop ‘two-in-one' SWCNT quantum devices that can switch from behaving as quantum-dot transistors for holes to quantum buses for electrons by changing the transistor's gate voltage |
| Databáze: | OpenAIRE |
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