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Carbon Nanotube Devices for Quantum Technology. MATERIALS 2022; 15:ma15041535. [PMID: 35208080 PMCID: PMC8878677 DOI: 10.3390/ma15041535] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/04/2022] [Accepted: 02/06/2022] [Indexed: 12/04/2022]
Abstract
Carbon nanotubes, quintessentially one-dimensional quantum objects, possess a variety of electrical, optical, and mechanical properties that are suited for developing devices that operate on quantum mechanical principles. The states of one-dimensional electrons, excitons, and phonons in carbon nanotubes with exceptionally large quantization energies are promising for high-operating-temperature quantum devices. Here, we discuss recent progress in the development of carbon-nanotube-based devices for quantum technology, i.e., quantum mechanical strategies for revolutionizing computation, sensing, and communication. We cover fundamental properties of carbon nanotubes, their growth and purification methods, and methodologies for assembling them into architectures of ordered nanotubes that manifest macroscopic quantum properties. Most importantly, recent developments and proposals for quantum information processing devices based on individual and assembled nanotubes are reviewed.
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Fullerene-Containing Electrically Conducting Electron Beam Resist for Ultrahigh Integration of Nanometer Lateral-Scale Organic Electronic Devices. Sci Rep 2017; 7:4306. [PMID: 28655933 PMCID: PMC5487332 DOI: 10.1038/s41598-017-04451-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 06/02/2017] [Indexed: 11/08/2022] Open
Abstract
An outstanding issue with organic devices is the difficulty of simultaneously controlling the lateral size and position of structures at submicron or nanometer scales. In this study, nanocomposite electron beam (EB) organic resists are proved to be excellent candidates for electrically conductive and/or memory component materials for submicron or nanometer lateral-scale organic electronic devices. The memory and the resist patterning characteristics are investigated for a positive electron beam resist of ZEP520a containing [6,6]-phenyl-C61 butyric acid methyl ester (PCBM). Regarding the memory characteristics, good programming and excellent retention characteristics are obtained for electrons. The carrier transfer and retention mechanisms are also investigated. Regarding the resist patterning characteristics, it is found that line patterns (square patterns) of ZEP520a containing PCBM can be made with widths (side lengths) of less than 200 nm by using an extremely simple process with only EB exposures and developments. The distribution of PCBM molecules or their aggregations is also clarified in ZEP520a containing PCBM. The results of this study open the door to the simple fabrication of highly integrated flexible memories and electrical wires as well as of single-electron or quantum devices, including quantum information devices and sensitive biosensors for multiplexed and simultaneous diagnoses.
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Deng GW, Zhu D, Wang XH, Zou CL, Wang JT, Li HO, Cao G, Liu D, Li Y, Xiao M, Guo GC, Jiang KL, Dai XC, Guo GP. Strongly Coupled Nanotube Electromechanical Resonators. NANO LETTERS 2016; 16:5456-62. [PMID: 27487412 DOI: 10.1021/acs.nanolett.6b01875] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Coupling an electromechanical resonator with carbon-nanotube quantum dots is a significant method to control both the electronic charge and the spin quantum states. By exploiting a novel microtransfer technique, we fabricate two separate strongly coupled and electrically tunable mechanical resonators for the first time. The frequency of the two resonators can be individually tuned by the bottom gates, and in each resonator, the electron transport through the quantum dot can be strongly affected by the phonon mode and vice versa. Furthermore, the conductance of either resonator can be nonlocally modulated by the other resonator through phonon-phonon interaction between the two resonators. Strong coupling is observed between the phonon modes of the two resonators, where the coupling strength larger than 200 kHz can be reached. This strongly coupled nanotube electromechanical resonator array provides an experimental platform for future studies of the coherent electron-phonon interaction, the phonon-mediated long-distance electron interaction, and entanglement state generation.
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Affiliation(s)
- Guang-Wei Deng
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Dong Zhu
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Xin-He Wang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University , Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100084, China
| | - Chang-Ling Zou
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Jiang-Tao Wang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University , Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100084, China
| | - Hai-Ou Li
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Gang Cao
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Di Liu
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Yan Li
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Ming Xiao
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Guang-Can Guo
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Kai-Li Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University , Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100084, China
| | - Xing-Can Dai
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University , Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100084, China
| | - Guo-Ping Guo
- Key Laboratory of Quantum Information, University of Science and Technology of China, Chinese Academy of Sciences , Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
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Gugliuzza A, Pingitore V, Miriello D, Drioli E. Functional carbon nanotubes for high-quality charge transfer and moisture regulation through membranes: structural and functional insights. Phys Chem Chem Phys 2015; 17:12919-26. [DOI: 10.1039/c5cp00750j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Electrically-responsive breathable membranes through which assisted charge and moisture transport are achieved by selective donor–acceptor-site interactions involving functional carbon nanotubes.
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Affiliation(s)
- Annarosa Gugliuzza
- Research Institute on Membrane Technology-National Research Council (ITM-CNR)
- Rende (CS)
- Italy
| | | | - Domenico Miriello
- University of Calabria
- DiBEST Department of Biology
- Ecology and Earth Sciences
- Rende (CS)
- Italy
| | - Enrico Drioli
- Research Institute on Membrane Technology-National Research Council (ITM-CNR)
- Rende (CS)
- Italy
- Department of Chemical Engineering and Materials
- University of Calabria
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5
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Kim BK, Seo M, Cho SU, Chung Y, Kim N, Bae MH, Kim JJ. Tunable double and triple quantum dots in carbon nanotube with local side gates. NANOTECHNOLOGY 2014; 25:295201. [PMID: 24981295 DOI: 10.1088/0957-4484/25/29/295201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate a simple but efficient design for forming tunable single, double and triple quantum dots (QDs) in a sub-μm-long carbon nanotube (CNT) with two major features that distinguish this design from that of traditional CNT QDs: the use of i) Al2Ox tunnelling barriers between the CNT and metal contacts and ii) local side gates for controlling both the height of the potential barrier and the electron-confining potential profile to define multiple QDs. In a serial triple QD, in particular, we find that a stable molecular coupling state exists between two distant outer QDs. This state manifests in anti-crossing charging lines that correspond to electron and hole triple points for the outer QDs. The observed results are also reproduced in calculations based on a capacitive interaction model with reasonable configurations of electrons in the QDs. Our design using artificial tunnel contacts and local side gates provides a simple means of creating multiple QDs in CNTs for future quantum-engineering applications.
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Affiliation(s)
- Bum-Kyu Kim
- Department of Physics, Chonbuk National University, Jeonju 561-756, Republic of Korea. Korea Research Institute of Standards and Science, Daejeon 305-340, Republic of Korea
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Sydoruk VA, Goß K, Meyer C, Petrychuk MV, Danilchenko BA, Weber P, Stampfer C, Li J, Vitusevich SA. Low-frequency noise in individual carbon nanotube field-effect transistors with top, side and back gate configurations: effect of gamma irradiation. NANOTECHNOLOGY 2014; 25:035703. [PMID: 24345726 DOI: 10.1088/0957-4484/25/3/035703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report on the influence of low gamma irradiation (10(4) Gy) on the noise properties of individual carbon nanotube (CNT) field-effect transistors (FETs) with different gate configurations and two different dielectric layers, SiO2 and Al2O3. Before treatment, strong generation-recombination (GR) noise components are observed. These data are used to identify several charge traps related to dielectric layers of the FETs by determining their activation energy. Investigation of samples with a single SiO2 dielectric layer as well as with two dielectric layers allows us to separate traps for each of the two dielectric layers. We reveal that each charge trap level observed in the side gate operation splits into two levels in top gate operation due to a different potential profile along the CNT channel. After gamma irradiation, only reduced flicker noise is registered in the noise spectra, which indicates a decrease of the number of charge traps. The mobility, which is estimated to be larger than 2 × 10(4) cm(2) V(-1) s(-1) at room temperature, decreases only slightly after radiation treatment, demonstrating high radiation hardness of the CNTs. Finally, we study the influence of Schottky barriers at the metal-nanotube interface on the transport properties of FETs, analyzing the behavior of the flicker noise component.
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Affiliation(s)
- V A Sydoruk
- Peter Grünberg Institute (PGI-6/8/9; IBG-2) and Jülich-Aachen Research Alliance for Future Information Technology (JARA-FIT), Forschungszentrum Jülich, D-52425 Jülich, Germany
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7
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Crochet JJ, Duque JG, Werner JH, Doorn SK. Photoluminescence imaging of electronic-impurity-induced exciton quenching in single-walled carbon nanotubes. NATURE NANOTECHNOLOGY 2012; 7:126-32. [PMID: 22231665 DOI: 10.1038/nnano.2011.227] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 11/18/2011] [Indexed: 05/26/2023]
Abstract
The electronic properties of single-walled carbon nanotubes can be altered by surface adsorption of electronic impurities or dopants. However, fully understanding the influence of these impurities is difficult because of the inherent complexity of the solution-based colloidal chemistry of nanotubes, and because of a lack of techniques for directly imaging dynamic processes involving these impurities. Here, we show that photoluminescence microscopy can be used to image exciton quenching in semiconducting single-walled carbon nanotubes during the early stages of chemical doping with two different species. The addition of AuCl(3) leads to localized exciton-quenching sites, which are attributed to a mid-gap electronic impurity level, and the adsorbed species are also found sometimes to be mobile on the surface of the nanotubes. The addition of H(2)O(2) leads to delocalized exciton-quenching hole states, which are responsible for long-range photoluminescence blinking, and are also mobile.
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Affiliation(s)
- Jared J Crochet
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, New Mexico, USA
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8
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Moriyama S, Morita Y, Watanabe E, Tsuya D, Uji S, Shimizu M, Ishibashi K. Fabrication of quantum-dot devices in graphene. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2010; 11:054601. [PMID: 27877364 PMCID: PMC5090623 DOI: 10.1088/1468-6996/11/5/054601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 12/22/2010] [Accepted: 10/15/2010] [Indexed: 06/01/2023]
Abstract
We describe our recent experimental results on the fabrication of quantum-dot devices in a graphene-based two-dimensional system. Graphene samples were prepared by micromechanical cleavage of graphite crystals on a SiO2/Si substrate. We performed micro-Raman spectroscopy measurements to determine the number of layers of graphene flakes during the device fabrication process. By applying a nanofabrication process to the identified graphene flakes, we prepared a double-quantum-dot device structure comprising two lateral quantum dots coupled in series. Measurements of low-temperature electrical transport show the device to be a series-coupled double-dot system with varied interdot tunnel coupling, the strength of which changes continuously and non-monotonically as a function of gate voltage.
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Affiliation(s)
- Satoshi Moriyama
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Yoshifumi Morita
- Faculty of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Eiichiro Watanabe
- Nanotechnology Innovation Center, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Daiju Tsuya
- Nanotechnology Innovation Center, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Shinya Uji
- Advanced Nano Materials Laboratory, NIMS, 3-13 Sakura, Tsukuba, Ibaraki 305-0003, Japan
| | - Maki Shimizu
- Advanced Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Koji Ishibashi
- Advanced Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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9
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Liu XL, Hug D, Vandersypen LMK. Gate-defined graphene double quantum dot and excited state spectroscopy. NANO LETTERS 2010; 10:1623-1627. [PMID: 20377196 DOI: 10.1021/nl9040912] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A double quantum dot is formed in a graphene nanoribbon device using three top gates. These gates independently change the number of electrons on each dot and tune the interdot coupling. Transport through excited states is observed in the weakly coupled double dot regime. We extract from the measurements all relevant capacitances of the double dot system, as well as the quantized level spacing.
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Affiliation(s)
- Xing Lan Liu
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
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10
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Moriyama S, Tsuya D, Watanabe E, Uji S, Shimizu M, Mori T, Yamaguchi T, Ishibashi K. Coupled quantum dots in a graphene-based two-dimensional semimetal. NANO LETTERS 2009; 9:2891-2896. [PMID: 19719107 DOI: 10.1021/nl9011535] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present an experimental demonstration of a graphene-based double quantum dot system, which exhibits single-electron transport of two lateral quantum dots coupled in series. Low-temperature transport measurements revealed honeycomb charge stability diagrams with a varied (from weak to strong) interdot tunnel-coupling regime, and we have extracted the relevant parameters associated with the double quantum dot system. These results are important for the realization of integrated quantum circuits in graphene-based electronics.
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Affiliation(s)
- Satoshi Moriyama
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan.
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11
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Steele GA, Gotz G, Kouwenhoven LP. Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes. NATURE NANOTECHNOLOGY 2009; 4:363-367. [PMID: 19498397 DOI: 10.1038/nnano.2009.71] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 02/23/2009] [Indexed: 05/27/2023]
Abstract
Quantum dots defined in carbon nanotubes are a platform for both basic scientific studies and research into new device applications. In particular, they have unique properties that make them attractive for studying the coherent properties of single-electron spins. To perform such experiments it is necessary to confine a single electron in a quantum dot with highly tunable barriers, but disorder has prevented tunable nanotube-based quantum-dot devices from reaching the single-electron regime. Here, we use local gate voltages applied to an ultraclean suspended nanotube to confine a single electron in both a single quantum dot and, for the first time, in a tunable double quantum dot. This tunability is limited by a novel type of tunnelling that is analogous to the tunnelling in the Klein paradox of relativistic quantum mechanics.
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Affiliation(s)
- G A Steele
- Kavli Institute of NanoScience, Delft University of Technology, Delft, The Netherlands.
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12
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Dicke M, van Loon JJA, Soler R. Chemical complexity of volatiles from plants induced by multiple attack. Nat Chem Biol 2009. [PMID: 19377458 DOI: 10.1038/nphys1266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
The attack of a plant by herbivorous arthropods can result in considerable changes in the plant's chemical phenotype. The emission of so-called herbivore-induced plant volatiles (HIPV) results in the attraction of carnivorous enemies of the herbivores that induced these changes. HIPV induction has predominantly been investigated for interactions between one plant and one attacker. However, in nature plants are exposed to a variety of attackers, either simultaneously or sequentially, in shoots and roots, causing much more complex interactions than have usually been investigated in the context of HIPV. To develop an integrated view of how plants respond to their environment, we need to know more about the ways in which multiple attackers can enhance, attenuate, or otherwise alter HIPV responses. A multidisciplinary approach will allow us to investigate the underlying mechanisms of HIPV emission in terms of phytohormones, transcriptional responses and biosynthesis of metabolites in an effort to understand these complex plant-arthropod interactions.
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Affiliation(s)
- Marcel Dicke
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands.
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Churchill HOH, Kuemmeth F, Harlow JW, Bestwick AJ, Rashba EI, Flensberg K, Stwertka CH, Taychatanapat T, Watson SK, Marcus CM. Relaxation and dephasing in a two-electron 13C nanotube double quantum dot. PHYSICAL REVIEW LETTERS 2009; 102:166802. [PMID: 19518737 DOI: 10.1103/physrevlett.102.166802] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Indexed: 05/27/2023]
Abstract
We use charge sensing of Pauli blockade (including spin and isospin) in a two-electron 13C nanotube double quantum dot to measure relaxation and dephasing times. The relaxation time T1 first decreases with a parallel magnetic field and then goes through a minimum in a field of 1.4 T. We attribute both results to the spin-orbit-modified electronic spectrum of carbon nanotubes, which at high field enhances relaxation due to bending-mode phonons. The inhomogeneous dephasing time T{2} is consistent with previous data on hyperfine coupling strength in 13C nanotubes.
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Affiliation(s)
- H O H Churchill
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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14
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Zippilli S, Morigi G, Bachtold A. Cooling carbon nanotubes to the phononic ground state with a constant electron current. PHYSICAL REVIEW LETTERS 2009; 102:096804. [PMID: 19392550 DOI: 10.1103/physrevlett.102.096804] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Indexed: 05/05/2023]
Abstract
We present a quantum theory of cooling of a mechanical resonator using back action with a constant electron current. The resonator device is based on a doubly clamped nanotube, which mechanically vibrates and acts as a double quantum dot for electron transport. Mechanical vibrations and electrons are coupled electrostatically using an external gate. The fundamental eigenmode is cooled by absorbing phonons when electrons tunnel through the double quantum dot. We identify the regimes in which ground-state cooling can be achieved for realistic experimental parameters.
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Affiliation(s)
- Stefano Zippilli
- Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
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15
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Gotz G, Steele GA, Vos WJ, Kouwenhoven LP. Real time electron tunneling and pulse spectroscopy in carbon nanotube quantum dots. NANO LETTERS 2008; 8:4039-4042. [PMID: 18928322 DOI: 10.1021/nl802892q] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We investigate a quantum dot (QD) in a carbon nanotube (CNT) in the regime where the QD is nearly isolated from the leads. An aluminum single electron transistor (SET) serves as a charge detector for the QD. We precisely measure and tune the tunnel rates into the QD in the range between 1 kHz and 1 Hz, using both pulse spectroscopy and real-time charge detection, and measure the excitation spectrum of the isolated QD.
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Affiliation(s)
- Georg Gotz
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands.
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16
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17
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Grove-Rasmussen K, Jørgensen HI, Hayashi T, Lindelof PE, Fujisawa T. A triple quantum dot in a single-wall carbon nanotube. NANO LETTERS 2008; 8:1055-1060. [PMID: 18314966 DOI: 10.1021/nl072948y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A top-gated single-wall carbon nanotube is used to define three coupled quantum dots in series between two electrodes. The additional electron number on each quantum dot is controlled by top-gate voltages allowing for current measurements of single, double, and triple quantum dot stability diagrams. Simulations using a capacitor model including tunnel coupling between neighboring dots captures the observed behavior with good agreement. Furthermore, anticrossings between indirectly coupled levels and higher order cotunneling are discussed.
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Affiliation(s)
- K Grove-Rasmussen
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198, Japan.
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18
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Liang CW, Sahakalkan S, Roth S. Electrical characterization of the mutual influences between gas molecules and single-walled carbon nanotubes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2008; 4:432-436. [PMID: 18348226 DOI: 10.1002/smll.200700436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Chen-Wei Liang
- Max-Planck-Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany
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19
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Hu Y, Churchill HOH, Reilly DJ, Xiang J, Lieber CM, Marcus CM. A Ge/Si heterostructure nanowire-based double quantum dot with integrated charge sensor. NATURE NANOTECHNOLOGY 2007; 2:622-625. [PMID: 18654386 DOI: 10.1038/nnano.2007.302] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 08/29/2007] [Indexed: 05/26/2023]
Abstract
One proposal for a solid-state-based quantum bit (qubit) is to control coupled electron spins on adjacent semiconductor quantum dots. Most experiments have focused on quantum dots made from III-V semiconductors; however, the coherence of electron spins in these materials is limited by hyperfine interactions with nuclear spins. Ge/Si core/shell nanowires seem ideally suited to overcome this limitation, because the most abundant nuclei in Ge and Si have spin zero and the nanowires can be chemically synthesized defect-free with tunable properties. Here, we present a double quantum dot based on Ge/Si nanowires in which we can completely control the coupling between the dots and to the leads. We also demonstrate that charge on the double dot can be detected by coupling it capacitively to an adjacent nanowire quantum dot. The double quantum dot and integrated charge sensor serve as an essential building block to form a solid-state qubit free of nuclear spin.
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Affiliation(s)
- Yongjie Hu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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20
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Konik RM. Kondo physics and exact solvability of double dots systems. PHYSICAL REVIEW LETTERS 2007; 99:076602. [PMID: 17930911 DOI: 10.1103/physrevlett.99.076602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Indexed: 05/25/2023]
Abstract
We study two double dot systems, one with dots in parallel and one with dots in series, and argue they admit an exact solution via the Bethe ansatz. In the case of parallel dots we exploit the exact solution to extract the behavior of the linear response conductance. The linear response conductance of the parallel dot system possesses multiple Kondo effects, including a Kondo effect enhanced by a nonpertubative antiferromagnetic RKKY interaction, has conductance zeros in the mixed valence regime, and obeys a nontrivial form of the Friedel sum rule.
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Affiliation(s)
- Robert M Konik
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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Angus SJ, Ferguson AJ, Dzurak AS, Clark RG. Gate-defined quantum dots in intrinsic silicon. NANO LETTERS 2007; 7:2051-5. [PMID: 17567176 DOI: 10.1021/nl070949k] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We report the fabrication and measurement of silicon quantum dots with tunable tunnel barriers in a narrow-channel field-effect transistor. Low-temperature transport spectroscopy is performed in both the many-electron ( approximately 100 electrons) regime and the few-electron ( approximately 10 electrons) regime. Excited states in the bias spectroscopy provide evidence of quantum confinement. These results demonstrate that depletion gates are an effective technique for defining quantum dots in silicon.
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Affiliation(s)
- Susan J Angus
- Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, Australia.
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Fuhrer A, Fröberg LE, Pedersen JN, Larsson MW, Wacker A, Pistol ME, Samuelson L. Few electron double quantum dots in InAs/InP nanowire heterostructures. NANO LETTERS 2007; 7:243-6. [PMID: 17297985 DOI: 10.1021/nl061913f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We report on fabrication of double quantum dots in catalytically grown InAs/InP nanowire heterostructures. In the few-electron regime, starting with both dots empty, our low-temperature transport measurements reveal a clear shell structure for sequential charging of the larger of the two dots with up to 12 electrons. The resonant current through the double dot is found to depend on the orbital coupling between states of different radial symmetry. The charging energies are well described by a capacitance model if next-neighbor capacitances are taken into account.
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Affiliation(s)
- Andreas Fuhrer
- The Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund, Sweden.
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