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Deng X, Gong K, Wang Y, Liu Z, Jiang K, Kang N, Zhang Z. Gate-Controlled Quantum Interference Effects in a Clean Single-Wall Carbon Nanotube p-n Junction. PHYSICAL REVIEW LETTERS 2023; 130:207002. [PMID: 37267546 DOI: 10.1103/physrevlett.130.207002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/13/2023] [Indexed: 06/04/2023]
Abstract
The precise control and deep understanding of quantum interference in carbon nanotube (CNT) devices are particularly crucial not only for exploring quantum coherent phenomena in clean one-dimensional electronic systems, but also for developing carbon-based nanoelectronics or quantum devices. Here, we construct a double split-gate structure to explore the Aharonov-Bohm (AB) interference effect in individual single-wall CNT p-n junction devices. For the first time, we achieve the AB modulation of conductance with coaxial magnetic fields as low as 3 T, where the flux through the tube is much smaller than the flux quantum. We further demonstrate direct electric-field control of the nonmonotonic magnetoconductance through a gate-tunable built-in electric field, which can be quantitatively understood in combination with the AB phase effect and Landau-Zener tunneling in a CNT p-n junction. Moreover, the nonmonotonic magnetoconductance behavior can be strongly enhanced in the presence of Fabry-Pérot resonances. Our Letter paves the way for exploring and manipulating quantum interference effects with combining magnetic and electric field controls.
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Affiliation(s)
- Xiaosong Deng
- Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics, School of Electronics, Peking University, Beijing 100871, China
| | - Kui Gong
- Hongzhiwei Technology (Shanghai) Co., Ltd. FL6, BLDG C2, No. 1599, Xinjinqiao Road, PuDong, ShangHai, China
| | - Yin Wang
- Hongzhiwei Technology (Shanghai) Co., Ltd. FL6, BLDG C2, No. 1599, Xinjinqiao Road, PuDong, ShangHai, China
| | - Zebin Liu
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics and Tsinghua Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
| | - Kaili Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics and Tsinghua Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
| | - Ning Kang
- Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics, School of Electronics, Peking University, Beijing 100871, China
- Hefei National laboratory, Hefei 230088, China
| | - Zhiyong Zhang
- Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics, School of Electronics, Peking University, Beijing 100871, China
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Nandkishore R, Levitov L. Common-path interference and oscillatory Zener tunneling in bilayer graphene p-n junctions. Proc Natl Acad Sci U S A 2011; 108:14021-5. [PMID: 21825159 PMCID: PMC3161540 DOI: 10.1073/pnas.1101352108] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Interference and tunneling are two signature quantum effects that are often perceived as the yin and yang of quantum mechanics: a particle simultaneously propagating along several distinct classical paths versus a particle penetrating through a classically inaccessible region via a single least-action path. Here we demonstrate that the Dirac quasiparticles in graphene provide a dramatic departure from this paradigm. We show that Zener tunneling in gapped bilayer graphene, which governs transport through p-n heterojunctions, exhibits common-path interference that takes place under the tunnel barrier. Due to a symmetry peculiar to the gapped bilayer graphene bandstructure, interfering tunneling paths form conjugate pairs, giving rise to high-contrast oscillations in transmission as a function of the gate-tunable bandgap and other control parameters of the junction. The common-path interference is solely due to forward-propagating waves; in contrast to Fabry-Pérot-type interference in resonant-tunneling structures, it does not rely on multiple backscattering. The oscillations manifest themselves in the junction I-V characteristic as N-shaped branches with negative differential conductivity. The negative dI/dV, which arises solely due to under-barrier interference, can enable new high-speed active-circuit devices with architectures that are not available in electronic semiconductor devices.
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Affiliation(s)
- Rahul Nandkishore
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Leonid Levitov
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139
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Chen W, Andreev AV, Glazman LI. Quantum criticality in a Mott pn junction in an armchair carbon nanotube. PHYSICAL REVIEW LETTERS 2011; 106:216801. [PMID: 21699326 DOI: 10.1103/physrevlett.106.216801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Indexed: 05/31/2023]
Abstract
In an armchair carbon nanotube pn junction the p and n regions are separated by a region of a Mott insulator, which can backscatter electrons only in pairs. We predict a quantum-critical behavior in such a pn junction. Depending on the junction's built-in electric field E, its conductance G scales either to zero or to 4e(2)/h as the temperature T is lowered. The two types of the G(T) dependence indicate the existence, at some special value of E, of an intermediate quantum-critical point with a finite conductance G<4e(2)/h. This makes the pn junction drastically different from a simple potential barrier in a Luttinger liquid.
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Affiliation(s)
- Wei Chen
- Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA
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Zhang LM, Fogler MM. Nonlinear screening and ballistic transport in a graphene p-n junction. PHYSICAL REVIEW LETTERS 2008; 100:116804. [PMID: 18517812 DOI: 10.1103/physrevlett.100.116804] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2007] [Indexed: 05/26/2023]
Abstract
We study the charge density distribution, the electric field profile, and the resistance of an electrostatically created lateral p-n junction in graphene. We show that the electric field at the interface of the electron and hole regions is strongly enhanced due to limited screening capacity of Dirac quasiparticles. Accordingly, the junction resistance is lower than estimated in previous literature.
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Affiliation(s)
- L M Zhang
- Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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