A single-atom transistor is a device that can open and close an electrical circuit by the controlled and reversible repositioning of one single atom. The single-atom transistor was invented and first demonstrated in 2004 by Prof. Thomas Schimmel and his team of scientists at the Karlsruhe Institute of Technology (former University of Karlsruhe). By means of a small electrical voltage applied to a control electrode, the so-called gate electrode, a single silver atom is reversibly moved in and out of a tiny junction, in this way closing and opening an electrical contact.
Therefore, the single-atom transistor works as an atomic switch or atomic relay, where the switchable atom opens and closes the gap between two tiny electrodes called source and drain. The single-atom transistor opens perspectives for the development of future atomic-scale logics and quantum electronics.
At the same time, the device of the Karlsruhe team of researchers marks the lower limit of miniaturization, as feature sizes smaller than one atom cannot be produced lithographically. The device represents a quantum transistor, the conductance of the source-drain channel being defined by the rules of quantum mechanics. It can be operated at room temperature and at ambient conditions, i.e. neither cooling nor vacuum are required.
Few atom transistors have been developed at Waseda University and at Italian CNR by Takahiro Shinada and Enrico Prati, who observed the Anderson-Mott transition in miniature by employing arrays of only two, four and six individually implanted As or P atoms.
- QFET (quantum field-effect transistor)
- ^ Xie, F.-Q.; Nittler, L.; Obermair, Ch.; Schimmel, Th. (2004-09-15). "Gate-Controlled Atomic Quantum Switch". Physical Review Letters. American Physical Society (APS). 93 (12): 128303. Bibcode:2004PhRvL..93l8303X. doi:10.1103/physrevlett.93.128303. ISSN 0031-9007. PMID 15447312.
- ^ Xie, Fang-Qing; Obermair, Christian; Schimmel, Thomas (2004). "Switching an electrical current with atoms: the reproducible operation of a multi-atom relay". Solid State Communications. Elsevier BV. 132 (7): 437–442. Bibcode:2004SSCom.132..437X. doi:10.1016/j.ssc.2004.08.024. ISSN 0038-1098.
- ^ Xie, F.-Q.; Maul, R.; Augenstein, A.; Obermair, Ch.; Starikov, E. B.; et al. (2008-12-10). "Independently Switchable Atomic Quantum Transistors by Reversible Contact Reconstruction". Nano Letters. 8 (12): 4493–4497. arXiv:0904.0904. Bibcode:2008NanoL...8.4493X. doi:10.1021/nl802438c. ISSN 1530-6984. PMID 19367974. S2CID 5191373.
- ^ Obermair, Ch.; Xie, F.-Q.; Schimmel, Th. (2010). "The Single-Atom Transistor: perspectives for quantum electronics on the atomic-scale". Europhysics News. EDP Sciences. 41 (4): 25–28. Bibcode:2010ENews..41d..25O. doi:10.1051/epn/2010403. ISSN 0531-7479.
- ^ Xie, Fangqing; Maul, Robert; Obermair, Christian; Wenzel, Wolfgang; Schön, Gerd; Schimmel, Thomas (2010-02-01). "Multilevel Atomic-Scale Transistors Based on Metallic Quantum Point Contacts". Advanced Materials. Wiley. 22 (18): 2033–2036. doi:10.1002/adma.200902953. ISSN 0935-9648. PMID 20544888. S2CID 28378720.
- ^ Prati, Enrico; Hori, Masahiro; Guagliardo, Filippo; Ferrari, Giorgio; Shinada, Takahiro (2012). "Anderson–Mott transition in arrays of a few dopant atoms in a silicon transistor". Nature Nanotechnology. Springer Science and Business Media LLC. 7 (7): 443–447. Bibcode:2012NatNa...7..443P. doi:10.1038/nnano.2012.94. ISSN 1748-3387. PMID 22751223.
- Beilstein TV Video of the Schimmel group: The single-atom transistor – perspectives for quantum electronics at room temperature (link offline)