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Search for "quantum dots" in Full Text gives 211 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.

Model systems for studying cell adhesion and biomimetic actin networks

  • Dorothea Brüggemann,
  • Johannes P. Frohnmayer and
  • Joachim P. Spatz

Beilstein J. Nanotechnol. 2014, 5, 1193–1202, doi:10.3762/bjnano.5.131

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  • . The successful incorporation of partly fluorescently labelled integrin αIIbβ3 into the GUVs was confirmed by confocal microscopy. Binding experiments of integrin-GUVs on surfaces and quantum dots coated with RGD ligands revealed that the incorporated integrins were biologically active. In reflection
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Published 01 Aug 2014

Enhanced photocatalytic hydrogen evolution by combining water soluble graphene with cobalt salts

  • Jing Wang,
  • Ke Feng,
  • Hui-Hui Zhang,
  • Bin Chen,
  • Zhi-Jun Li,
  • Qing-Yuan Meng,
  • Li-Ping Zhang,
  • Chen-Ho Tung and
  • Li-Zhu Wu

Beilstein J. Nanotechnol. 2014, 5, 1167–1174, doi:10.3762/bjnano.5.128

Graphical Abstract
  • artificial catalyst for photocatalytic hydrogen evolution [23], for example, was simply constructed in situ from earth-abundant cobalt salts and CdTe quantum dots. As a new carbon material with large surface area and excellent electrical properties, graphene has raised much attention since 2004 [24][25][26
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Published 29 Jul 2014

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

  • Pia Sundberg and
  • Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Graphical Abstract
  • decline [77]. Different combinations of terephthalaldehyde, 1,4-diaminobenzene and ethanedihydrazide have been used to fabricate quantum dots of varying lengths: These thin films showed promise for sensitization in photovoltaic devices [79][80]. Hybrid inorganic–organic thin films Since the first
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Published 22 Jul 2014

Photocatalysis

  • Rong Xu

Beilstein J. Nanotechnol. 2014, 5, 1071–1072, doi:10.3762/bjnano.5.119

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  • and morphological tuning, in particular for hybrid materials systems such as Ag–ZnO, VTi/MCM-41, are important toward achieving higher solar energy conversion efficiencies. In a couple of reports, materials alternative to conventional metal oxides, for example, reduced graphene oxide, graphene quantum
  • dots integrated with TiO2 nanotube arrays, and carbon nitride, have been explored to construct photocatalysts with enhanced performances. On the other hand, molecular catalysts have an advantage in design flexibility and structural tunability. A contribution based on the investigation of molecular
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Published 16 Jul 2014

Functionalized nanostructures for enhanced photocatalytic performance under solar light

  • Liejin Guo,
  • Dengwei Jing,
  • Maochang Liu,
  • Yubin Chen,
  • Shaohua Shen,
  • Jinwen Shi and
  • Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

Graphical Abstract
  • high crystallinity, high surface area and unique microstructure [63]. As the crystal size of the semiconductor is close to the exciton Bohr radius, its bandgap can be enlarged with a reduced crystal size due to the quantum confinement effect. Therefore, we have synthesized Co3O4 quantum dots (3–4 nm
  • Co3O4 is not negative enough to reduce H+. Compared with bulk Co3O4, Co3O4 quantum dots have a wider bandgap. Valence-band XPS spectra showed that the valance band maxima (VBM) of Co3O4 quantum dots and bulk Co3O4 are almost at the same position, implying that the enlarged bandgap of Co3O4 quantum dots
  • was mainly ascribed to the conduction band minimum (CBM) upshift. Due to the negative shift of the conduction band, Co3O4 quantum dots can split pure water into O2 and H2 stoichiometrically under visible light irradiation without any cocatalyst. This is the first report to date of Co3O4 photocatalysts
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Published 09 Jul 2014

Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

  • Li-wei Liu,
  • Si-yi Hu,
  • Ying Pan,
  • Jia-qi Zhang,
  • Yue-shu Feng and
  • Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

Graphical Abstract
  • applications and may offer a new direction for the early detection of cancer in humans. Keywords: bioimaging; CdS/ZnS quantum dots; Pluronic F127; Introduction Over the past decade, the use of semiconductor nanocrystals or quantum dots (QDs) has developed remarkably due to their unique features. Compared to
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Published 27 Jun 2014

Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

  • Claudio Davet Gutiérrez-Lazos,
  • Mauricio Ortega-López,
  • Manuel A. Pérez-Guzmán,
  • A. Mauricio Espinoza-Rivas,
  • Francisco Solís-Pomar,
  • Rebeca Ortega-Amaya,
  • L. Gerardo Silva-Vidaurri,
  • Virginia C. Castro-Peña and
  • Eduardo Pérez-Tijerina

Beilstein J. Nanotechnol. 2014, 5, 881–886, doi:10.3762/bjnano.5.100

Graphical Abstract
  • , 350 and 400 °C. On the other hand, oleic acid is a green organic ligand, which has been successfully used in preparing a great variety of colloidal materials [15][25][26], including CdTe quantum dots [27][28][29]. This work presents our early results on the elaboration of CdTe-based inks for potential
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Published 20 Jun 2014

Resonance of graphene nanoribbons doped with nitrogen and boron: a molecular dynamics study

  • Ye Wei,
  • Haifei Zhan,
  • Kang Xia,
  • Wendong Zhang,
  • Shengbo Sang and
  • Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 717–725, doi:10.3762/bjnano.5.84

Graphical Abstract
  • synthesised through chemical functionalization with hydroxy and methyl groups or hydrogen [10], the decoration with quantum dots [11], noble metal nanoparticles (NPs) [12], or complex biomolecular structures [13][14]. A number of works have been conducted to investigate the properties of graphene derivatives
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Published 27 May 2014

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

  • Hongjun Chen and
  • Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

Graphical Abstract
  • quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent
  • utilize solar energy for the investigation of photocatalysis. There is a large array of excellent review articles covering selected aspects of the design of photocatalysts in the past years. In this review, we focus on a variety of nanostructures including quantum dots, plasmonic metal nanostructures and
  • visible light photocatalysis which is important for the photo-degradation of organic pollutants and the splitting of water for the production of H2 fuel. In this section, we mainly focus on the different nanostructures like quantum dots, plasmonic metal nanostructures, and carbon-based nanostructures used
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Published 23 May 2014

A visible-light-driven composite photocatalyst of TiO2 nanotube arrays and graphene quantum dots

  • Donald K. L. Chan,
  • Po Ling Cheung and
  • Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

Graphical Abstract
  • incorporation of graphene quantum dots could extend the photo-response of the nanotubes to the visible-light range. Graphene quantum dot-sensitized TiO2 nanotube arrays were synthesized by covalently coupling these two materials. The product was characterized by Fourier-transform infrared spectrometry (FTIR
  • light irradiation. Keywords: anodic oxidation; graphene quantum dots; photocatalyst; photodegradation; TiO2 nanotube arrays; Introduction Semiconductor-mediated photocatalysis is a promising technique for the conversion of solar energy as well as degradation of organic pollutants in air and water [1
  • , graphene sheets are usually micrometer-sized and they can hardly be introduced into efficient nano-sized photocatalysts on a solid support, for example, TNAs. Zero-dimensional graphene quantum dots (GQDs) are defined as few-layered graphene with lateral dimensions smaller than 100 nm [28]. Due to quantum
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Published 22 May 2014

Injection of ligand-free gold and silver nanoparticles into murine embryos does not impact pre-implantation development

  • Ulrike Taylor,
  • Wiebke Garrels,
  • Annette Barchanski,
  • Svea Peterson,
  • Laszlo Sajti,
  • Andrea Lucas-Hahn,
  • Lisa Gamrad,
  • Ulrich Baulain,
  • Sabine Klein,
  • Wilfried A. Kues,
  • Stephan Barcikowski and
  • Detlef Rath

Beilstein J. Nanotechnol. 2014, 5, 677–688, doi:10.3762/bjnano.5.80

Graphical Abstract
  • , nanoparticles were found to be stopped by the placental barrier [4][5][6]. The majority of authors, however, observed placental crossing. This encompasses studies of nanoparticles composed of gold [7][8], titanium dioxide [9][10], CdTe/CdS quantum dots [11], and polystyrene [12]. Thus, transplacental crossing
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Published 21 May 2014

Encapsulation of nanoparticles into single-crystal ZnO nanorods and microrods

  • Jinzhang Liu,
  • Marco Notarianni,
  • Llew Rintoul and
  • Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 485–493, doi:10.3762/bjnano.5.56

Graphical Abstract
  • . Thus the options for lasing wavelength and resonant mode orders are limited. There is a large variety of nanoparticles that have various luminescent properties and potential applications. Luminescent nanoparticles including semiconductor quantum dots, nanodiamonds (NDs) with nitrogen-vacancy (NV
  • ) centres, and dye-doped polymer nanobeads, etc., have wide applications based on their luminescent properties. Luminescent NDs can be used for magnetic sensing [14]; dye-doped polymer nanobeads can act as laser gain media [15], depending on the selection of dye molecules. Semiconductor quantum dots can be
  • interesting because they are not only optical cavities but also components for developing UV light-emitting diodes (LEDs). If luminescent quantum dots or dye-doped polymer nanobeads can be encapsulated into a ZnO nano/microrod that is integrated into a LED, the UV emission of ZnO can act as an excitation
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Published 16 Apr 2014

Photoactivation of luminescence in CdS nanocrystals

  • Valentyn Smyntyna,
  • Bogdan Semenenko,
  • Valentyna Skobeeva and
  • Nikolay Malushin

Beilstein J. Nanotechnol. 2014, 5, 355–359, doi:10.3762/bjnano.5.40

Graphical Abstract
  • interfacial processes and the mechanism of the amplification of the quantum yield of quantum dots are still a subject of active discussion and require further clarification [5]. As noted in [2][3][4][5][10][11][12][13][14] the properties of luminescence are strongly dependent on the technology of the quantum
  • dots synthesis, nature of the coating agent, surrounding atmosphere, density of the quantum dots, and the radiation intensity. Note that so far the unusual behaviour of the irradiation-induced QD luminescence has been observed either in QDs of CdSe or in nanocrystals of CdSe/ZnS/TOPO and has been
  • mainly related to a single exciton emission band. Therefore, it is interesting to study the luminescent properties of quantum dots of other materials and other matrices that contain the QDs. Unlike [1][2][4][5] this paper investigates the luminescence of cadmium sulfide nanocrystals dispersed in a
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Published 25 Mar 2014

Optical near-fields & nearfield optics

  • Alfred J. Meixner and
  • Paul Leiderer

Beilstein J. Nanotechnol. 2014, 5, 186–187, doi:10.3762/bjnano.5.19

Graphical Abstract
  • numerous other applications of near-field enhancement, e.g., in biosensors, solar cells and semiconductor quantum dots to name but a few. A challenging question, investigated in this series by Esmann et al. [3], is how light can be most efficiently coupled into sub-wavelength dimensions by means of an
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Published 19 Feb 2014

Study of mesoporous CdS-quantum-dot-sensitized TiO2 films by using X-ray photoelectron spectroscopy and AFM

  • Mohamed N. Ghazzal,
  • Robert Wojcieszak,
  • Gijo Raj and
  • Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 68–76, doi:10.3762/bjnano.5.6

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  • Bruxelles 61 - 5000 Namur, Belgique Institute of Chemistry, University of Sao Paulo, USP, São Paulo, 05508-000, SP, Brazil 10.3762/bjnano.5.6 Abstract CdS quantum dots were grown on mesoporous TiO2 films by successive ionic layer adsorption and reaction processes in order to obtain CdS particles of various
  • . Keywords: AFM; CdS; heterojunction; particle size; quantum dots; TiO2; XPS; Introduction To sensitize the photocatalyst TiO2 with cadmium sulfide quantum dots (QDs-CdS) is a well-established concept that is of great relevance in different applications. The most popular of these applications are
  • formation of aggregates make the estimation of the average particle size of the CdS nanoparticles by AFM very challenging and result in overestimated values. UV–vis diffuse reflectance spectroscopy The absorption spectra recorded for various increasing deposition cycles of CdS quantum dots are shown in
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Published 20 Jan 2014

Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

  • Irina V. Martynenko,
  • Anna O. Orlova,
  • Vladimir G. Maslov,
  • Alexander V. Baranov,
  • Anatoly V. Fedorov and
  • Mikhail Artemyev

Beilstein J. Nanotechnol. 2013, 4, 895–902, doi:10.3762/bjnano.4.101

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  • University, Minsk, Belarus 10.3762/bjnano.4.101 Abstract The photoexcitation energy transfer is found and investigated in complexes of CdSe/ZnS cationic quantum dots and chlorin e6 molecules formed by covalent bonding and electrostatic interaction in aqueous solution and in porous track membranes. The
  • quantum dots and chlorin e6 molecules form stable complexes that exhibit Förster resonance energy transfer (FRET) from quantum dots to chlorin e6 regardless of complex formation conditions. Competitive channels of photoexcitation energy dissipation in the complexes, which hamper the FRET process, were
  • found and discussed. Keywords: chlorin e6; FRET; quantum dots; track membrane; Introduction During the last decade, photophysical properties of the complexes formed by colloidal quantum dots (QDs) and organic molecules, in particular, complexes of QDs and tetrapyrrole compounds, were widely
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Published 13 Dec 2013

Advances in nanomaterials

  • Herbert Gleiter,
  • Horst Hahn and
  • Thomas Schimmel

Beilstein J. Nanotechnol. 2013, 4, 805–806, doi:10.3762/bjnano.4.91

Graphical Abstract
  • these contributions is found in this Thematic Series in the form of original research articles reflecting recent advances in nanomaterials. The articles in this Thematic Series highlight recent developments, from nanoporous polymers to graphene quantum dots, from concepts for designing magnetic
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Published 27 Nov 2013

Mapping of plasmonic resonances in nanotriangles

  • Simon Dickreuter,
  • Julia Gleixner,
  • Andreas Kolloch,
  • Johannes Boneberg,
  • Elke Scheer and
  • Paul Leiderer

Beilstein J. Nanotechnol. 2013, 4, 588–602, doi:10.3762/bjnano.4.66

Graphical Abstract
  • , in particular metallic nanoparticles, which display pronounced plasmon resonances. These highly localized near fields of plasmonic particles have been demonstrated to be a very efficient tool for nanomachining [1], optical pumping of nanoscale objects such as quantum dots [2], surface enhanced Raman
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Published 30 Sep 2013

Magnetic anisotropy of graphene quantum dots decorated with a ruthenium adatom

  • Igor Beljakov,
  • Velimir Meded,
  • Franz Symalla,
  • Karin Fink,
  • Sam Shallcross and
  • Wolfgang Wenzel

Beilstein J. Nanotechnol. 2013, 4, 441–445, doi:10.3762/bjnano.4.51

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  • motivate our present study of the MAE of Ru adatoms on a graphene flake. Methods As the system of choice, triangular hydrogen-saturated graphene flakes (or graphene quantum dots) were investigated, comprising 90 and 97 carbon atoms for two different edge types, armchair and zigzag (AGQD and ZGQD
  • structure of the armchair-graphene (AGQD) and zigzag-graphene (ZGQD) quantum dots in the pristine state, i.e., without decoration by a Ru atom. (The geometric structure may be seen in Figure 1.) While the AGQD has no intrinsic moment, the ZGQD in contrast is found to have an intrinsic moment of 7 μB. This
  • reported by Lieb [27]. As we shall subsequently see, this difference in the magnetic state of the pristine graphene quantum dots leads to a qualitatively different behaviour of the magnetic anisotropy of the absorbed Ru atom. Before considering in detail the magnetic state of the Ru adatom, however, we
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Published 10 Jul 2013

Ni nanocrystals on HOPG(0001): A scanning tunnelling microscope study

  • Michael Marz,
  • Keisuke Sagisaka and
  • Daisuke Fujita

Beilstein J. Nanotechnol. 2013, 4, 406–417, doi:10.3762/bjnano.4.48

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  • reported [1]. Keywords: clusters; growth mode; Ni; nickel; Introduction Metallic nanoparticles have been widely studied in the past few decades owing to their broad range of applications, such as catalysis [2][3][4], quantum dots [5] or chemical sensors [6]. Moreover, nano particles consisting of only
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Published 28 Jun 2013

Horizontal versus vertical charge and energy transfer in hybrid assemblies of semiconductor nanoparticles

  • Gilad Gotesman,
  • Rahamim Guliamov and
  • Ron Naaman

Beilstein J. Nanotechnol. 2012, 3, 629–636, doi:10.3762/bjnano.3.72

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  • . Keywords: charge transfer; energy transfer; nanoparticles; organic linker; quantum dots; Introduction Self-assembled structures of semiconductor nanoparticles (NPs) are viewed as a possible avenue for producing photovoltaic devices with efficient collection of light and charge separation processes [1
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Published 06 Sep 2012

P-wave Cooper pair splitting

  • Henning Soller and
  • Andreas Komnik

Beilstein J. Nanotechnol. 2012, 3, 493–500, doi:10.3762/bjnano.3.56

Graphical Abstract
  • Cooper pair in spin space (using ferromagnets [10][11][12] or Luttinger liquids [2]), or in energy space (using quantum dots [1][13], coupling to an electromagnetic mode [14], an appropriate voltage bias [15][16][17][18] or ac-bias [19]). Filtering using quantum dots with large onsite interaction has
  • [58][64], since its origin does not lie in the precise form of the energy dependence of the transmission coefficients. Experiments in the direction of the above-described proposal have already been realized [73]. Multiterminal hybrid systems with embedded quantum dots [74] also based on InAs nanowires
  • level considered here, are present and have a characteristic location and width associated with interactions. Therefore the general scenario should be robust. However, one should bear in mind that for more extended quantum dots or nanowires disorder could play an important role as mentioned in [65] and
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Published 06 Jul 2012

Combining nanoscale manipulation with macroscale relocation of single quantum dots

  • Francesca Paola Quacquarelli,
  • Richard A. J. Woolley,
  • Martin Humphry,
  • Jasbiner Chauhan,
  • Philip J. Moriarty and
  • Ashley Cadby

Beilstein J. Nanotechnol. 2012, 3, 324–328, doi:10.3762/bjnano.3.36

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  • , University of Nottingham, Nottingham, NG7 2RD UK Phase Focus Limited, The Kroto Innovation Centre, The University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ, UK 10.3762/bjnano.3.36 Abstract We have controllably positioned, with nanometre precision, single CdSe quantum dots referenced to a
  • registration template such that the location of a given nanoparticle on a macroscopic (≈1 cm2) sample surface can be repeatedly revisited. The atomically flat sapphire substrate we use is particularly suited to optical measurements of the isolated quantum dots, enabling combined manipulation–spectroscopy
  • experiments on a single particle. Automated nanoparticle manipulation and imaging routines have been developed so as to facilitate the rapid assembly of specific nanoparticle arrangements. Keywords: automation; nanoscale manipulation; nanotechnology; quantum dots; single molecule spectroscopy; Introduction
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Published 10 Apr 2012

Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

  • Fabien Castanié,
  • Laurent Nony,
  • Sébastien Gauthier and
  • Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

Graphical Abstract
  • were also observed experimentally by STM on GNR or on graphene quantum dots [79][114][115]. A calculated FM-AFM image acquired with the n-AFM in the frozen-atoms regime is shown in Figure 4a. Here, the setpoint is Hset = 3.8 Å and the Δf corrugation is 81.7 Hz. At this setpoint, it is not possible to
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Published 02 Apr 2012

Current-induced forces in mesoscopic systems: A scattering-matrix approach

  • Niels Bode,
  • Silvia Viola Kusminskiy,
  • Reinhold Egger and
  • Felix von Oppen

Beilstein J. Nanotechnol. 2012, 3, 144–162, doi:10.3762/bjnano.3.15

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  • nanoelectromechanical systems (NEMS). The coupling between mechanical and electronic degrees of freedom is the defining characteristic of NEMS [9][10], such as suspended quantum dots [11], carbon nanotubes or graphene sheets [12][13], one-dimensional wires [14], and molecular junctions [15][16]. For these systems, a
  • –Condon blockade effect, a phononic analogue of the Coulomb blockade in quantum dots [25][26][27]. In the opposite regime, electrons tunnel through the nanostructure rapidly, observing a quasistatic configuration of the vibrational modes, but affecting their dynamics profoundly at the same time [18][19
  • model can be seen to be inspired by a double dot on a suspended carbon nanotube, or an H2 molecule in a break junction. The model is depicted schematically in Figure 2. The bare dot Hamiltonian corresponds to degenerate electronic states ε0, localized on the left and right atoms or quantum dots, with
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Published 20 Feb 2012
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