Spin Filtering through Single‐Wall Carbon Nanotubes Functionalized with Single‐Stranded DNA

Alam, Kazi M.; Pramanik, Sandipan

doi:10.1002/adfm.201500494

Cited by 60 publications

(76 citation statements)

References 41 publications

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“…The CISS effect relates to the ability of chiral molecules to transmit electrons in a spin-selective manner, hence the molecules act as spin filters. 6,7 Several chiral molecular species including DNA, [8][9][10][11][12] oligopeptides, [13][14][15] bacteriorhodopsin (bR), 16,17 a chiral conductive polymer, 18 1, 2-diphenyl-1,2-ethanediol (DPED), 19 helicenes, 20 and recently chiral CdSe quantum dots 21 have demonstrated efficient spin filtering. The spin filtering ability can be tuned by various means, for example, by varying the length of the chiral molecule, 8,9,13 by exposure to light, 22 or by varying the temperature.…”

Section: Introductionmentioning

confidence: 99%

Structure dependent spin selectivity in electron transport through oligopeptides

Kiran

Cohen

Naaman

2016

The Journal of Chemical Physics

108

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The chiral-induced spin selectivity (CISS) effect entails spin-selective electron transmission through chiral molecules. In the present study, the spin filtering ability of chiral, helical oligopeptide monolayers of two different lengths is demonstrated using magnetic conductive probe atomic force microscopy. Spin-specific nanoscale electron transport studies elucidate that the spin polarization is higher for 14-mer oligopeptides than that of the 10-mer. We also show that the spin filtering ability can be tuned by changing the tip-loading force applied on the molecules. The spin selectivity decreases with increasing applied force, an effect attributed to the increased ratio of radius to pitch of the helix upon compression and increased tilt angles between the molecular axis and the surface normal. The method applied here provides new insights into the parameters controlling the CISS effect. C 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

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Section: Introductionmentioning

confidence: 99%

Structure dependent spin selectivity in electron transport through oligopeptides

Kiran

Cohen

Naaman

2016

The Journal of Chemical Physics

108

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“…This effective field stabilizes one spin orientation of the electrons over the other and gives rise to a spin-dependent transmission (11). Since its discovery, the effect has been observed experimentally and verified in different systems (12)(13)(14)(15)(16)(17)(18).In the first part of this manuscript, we describe how the spin polarization in monolayers of chiral molecules was measured, and in the second part, we present calculations on model systems and discuss how this phenomenon introduces considerations for describing the interaction between chiral molecules. …”

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confidence: 99%

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confidence: 99%

Chirality-induced spin polarization places symmetry constraints on biomolecular interactions

Kumar

Capua

Kesharwani

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

180

247

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Noncovalent interactions between molecules are key for many biological processes. Necessarily, when molecules interact, the electronic charge in each of them is redistributed. Here, we show experimentally that, in chiral molecules, charge redistribution is accompanied by spin polarization. We describe how this spin polarization adds an enantioselective term to the forces, so that homochiral interaction energies differ from heterochiral ones. The spin polarization was measured by using a modified Hall effect device. An electric field that is applied along the molecules causes charge redistribution, and for chiral molecules, a Hall voltage is measured that indicates the spin polarization. Based on this observation, we conjecture that the spin polarization enforces symmetry constraints on the biorecognition process between two chiral molecules, and we describe how these constraints can lead to selectivity in the interaction between enantiomers based on their handedness. Model quantum chemistry calculations that rigorously enforce these constraints show that the interaction energy for methyl groups on homochiral molecules differs significantly from that found for heterochiral molecules at van der Waals contact and shorter (i.e., ∼0.5 kcal/mol at 0.26 nm).spin | chirality | enantioselectivity | biorecognition | exchange interaction T he wealth of information on protein structure has led to a much better understanding of the relation between structure and function in biomolecular processes and biological machines (1); however, basic phenomena remain unexplained in terms of structure-function relationships. Biorecognition, which is based on noncovalent interactions between molecules, retains mysteries, and its calculation evades first principles theory (2, 3). This failure suggests that some essential features are not included in our current description of these interactions (4,5). In this study, we show that charge polarization, which occurs in any biorecognition event, is accompanied by spin polarization for chiral molecules, an effect that is missing in most treatments. The subsequent magnetic interaction energies are small and therefore, play no significant role in the interactions; however, the spin polarization constrains the symmetry of the wave function(s) involved with the intermolecular interaction, so that significant differences in energy emerge for interactions between molecules of the same chirality and those of opposite chirality. Thus, this phenomenon may impact quantitative modeling of biorecognition events and contribute to our understanding of enantiorecognition in nature (6).Nucleotides, amino acids, and sugars are chiral; namely, they do not possess mirror plane symmetry but have symmetry like a "hand" (cheir in Greek). Force field models for the interaction between biomolecules do not account for spin polarization or include terms with chiral symmetry. Noncovalent interactions between biomolecules are commonly described classically by way of force fields, which are constructed from their geometrie...

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“…Actually, DNA molecules wrapped around single-walled carbon nanotubes are shown to induce a helicoidal electric field due to the polar nature of the adsorbed DNA molecule [25] and spin-polarized currents are produced depending on the symmetry of the DNA molecule-nanotube hybrid system. Our results show that it could be possible to engineer particular defect configurations on the CNTs, opening new routes for their use in spintronic devices [32]. …”

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confidence: 82%

Defect-enhanced Rashba spin-polarized currents in carbon nanotubes

et al. 2017

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The production of spin-polarized currents in pristine carbon nanotubes with Rashba spin-orbit interaction has been shown to be very sensitive to the symmetry of the tubes and the geometry of the setup. Here we analyze the role of defects on the spin quantum conductances of metallic carbon nanotubes due to an external electric field. We show that localized defects, such as adsorbed hydrogen atoms or pentagon-heptagon pairs, increase the Rashba spin-polarized current. Moreover, this enhancement takes place for energies closer to the Fermi energy as compared to the response of pristine tubes. Such increment can be even larger when several equally spaced defects are introduced into the system. We explore different arrangements of defects, showing that for certain geometries there are flips of the spin-polarized current and even transport suppression. Our results indicate that spin valve devices at the nanoscale may be achieved via defect engineering in carbon nanotubes.

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Spin Filtering through Single‐Wall Carbon Nanotubes Functionalized with Single‐Stranded DNA

Cited by 60 publications

References 41 publications

Structure dependent spin selectivity in electron transport through oligopeptides

Structure dependent spin selectivity in electron transport through oligopeptides

Chirality-induced spin polarization places symmetry constraints on biomolecular interactions

Defect-enhanced Rashba spin-polarized currents in carbon nanotubes

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