DOCSLIB.ORG

Logic Circuits with Carbon Nanotube Transistors

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Logic Circuits with Carbon Nanotube Transistors R EPORTS general, p-Si NWs grown with a higher dopant ratio 24. The OR and AND gates were assembled by using p-n 26. J. I. Pankov, T. D. Moustakas, Gallium Nitride (GaN) I ϭ (SiH4:B2H6 1000:1) have lower resistance and junctions (diode logic) and do not exhibit voltage gain; (Academic Press, San Diego, 1998), pp. 259Ð265. smaller on/off ratios of ϳ103; those synthesized with however, they would show gain if implemented by 27. N. J. Watkins, G. W. Wicks, Yongli Gao, Appl. Phys. a lower dopant ratio (6000:1) have higher resistance using cNW-FETs. For example, logic OR can be imple- Lett. 75, 2602 (1999). ϳ 4 5 and larger on/off ratios of 10 to 10 . In addition, mented with the NOR gate by reversing the 5-V bias 28. We thank H. Park for helpful discussion. C.M.L. ac- the carrier mobility typically varies from 30 to 200 and ground connections to the p-Si NW. The AND knowledges support of this work by the Office of cm2/V-s, depending on doping. function could also be implemented by using cNW-FETs Naval Research and the Defense Advanced Projects in parallel (versus series for OR). In addition, we note 22. S. M. Sze, Semiconductor Devices, Physics and Tech- Research Agency. nology ( Wiley, New York, 1985), pp. 208Ð210. that both p- and n-channel transistors are possible and 23. P. Horowitz, W. Hill, The Art of Electronics (Cam- would enable reduced power dissipation. bridge Univ. Press, Cambridge, 1989). 25. Y. Huang, X. Duan & C. M. Lieber, unpublished results. 12 September 2001; accepted 16 October 2001 ter of about 1 nm and that are situated on top of Logic Circuits with Carbon the Al gate wires. Their coordinates are regis- tered with respect to alignment markers. Finally, Nanotube Transistors contact electrodes and interconnect wires are fabricated with electron-beam lithography by Adrian Bachtold,* Peter Hadley, Takeshi Nakanishi, Cees Dekker† evaporating Au directly on the nanotube without an adhesion layer. We demonstrate logic circuits with field-effect transistors based on single Very strong doping of the nanotube channel carbon nanotubes. Our device layout features local gates that provide excellent can be achieved with this layout (Fig. 2A) (20). capacitive coupling between the gate and nanotube, enabling strong electro- Starting from a negative gate voltage Vg, the static doping of the nanotube from p-doping to n-doping and the study of the current I first decreases, then becomes immea- nonconventional long-range screening of charge along the one-dimensional surably small, and finally increases again. This nanotubes. The transistors show favorable device characteristics such as high indicates that Vg shifts the Fermi level succes- gain (Ͼ10), a large on-off ratio (Ͼ105), and room-temperature operation. sively from the valence band (accumulation re- Importantly, the local-gate layout allows for integration of multiple devices on gime) to the gap (depletion), and finally to the a single chip. Indeed, we demonstrate one-, two-, and three-transistor circuits conduction band (inversion) of the semicon- that exhibit a range of digital logic operations, such as an inverter, a logic NOR, ducting nanotube. The nearby Al gate thus a static random-access memory cell, and an ac ring oscillator. makes it possible to change the doping of the nanotube over the full range from the p-tothe The anticipated limits to the further miniatur- oxidized Si wafer (6, 7, 9), the tip of an atomic n-doped regime. ization of microelectronics have led to in- force microscope (10–12), a second nanotube Our nanotube transistors can be classified as tense research directed toward the develop- (13), an ionic solution (14), or a capping Al enhancement-mode p-type FETs (21), because a ment of molecular electronics (1). The use of film (15). The layouts of these devices do not strong modulation of the current through the single-wall carbon nanotubes has stimulated allow integration of multiply connected devices nanotube FET is possible when a small negative these efforts, because these molecules exhibit (16). For example, the most popular nanotube- gate voltage is applied. The current versus bias a range of suitable properties for nanoelec- transistor layout uses a backgate, which applies voltage Vsd characteristics (Fig. 3) are typical for tronics. Various basic single-nanotube com- the same gate voltage to all transistors on the FETs (22). From the data in Figs. 2 and 3, we ponents have recently been demonstrated, chip. In contrast, our gate consists of a micro- can extract a transconductance of our nanotube such as molecular wires, diodes, field-effect fabricated Al wire with a well-insulating native transistors of 0.3 ␮S and a lower limit of the 5 transistors, and single-electron transistors (2– Al2O3 layer (17), which lies beneath a semi- on/off ratio of at least 10 . The maximum cur- 8). The next challenge in the development of conducting nanotube that is electrically contact- rent at which the nanotube transistor can operate molecular electronics is to go beyond single- ed to two Au electrodes (Fig. 1, A and B). In is on the order of 100 nA and the on-resistance ϭ ϭ molecule components and integrate such de- this configuration, the Al2O3 thickness of a few is 26 megaohms for Vsd –1.3 V and Vg –1.3 vices onto a chip to demonstrate digital logic nanometers is much shorter than the separation V. operations. Here, we report such logic cir- between the contact electrodes (ϳ100 nm), en- For any further development of operational cuits composed of single-nanotube field-ef- abling an excellent capacitive coupling between logic circuits, a gain (Ͼ1) at large bias voltage fect transistors. In addition to the realization the gate and the nanotube. Moreover, different is a crucial requirement, because the output of of logic circuits, our new device layout also local Al gates can easily be patterned such that one logic structure must be able to drive the enables substantial electrostatic doping for each one addresses a different nanotube transis- input of the next logic structure. The output modest gate voltages, which allows us to tor. This layout thus allows the integration of typically has to provide a voltage swing of study the nonconventional screening of multiple nanotube field-effect transistors about 1 V. Figure 3 indicates that in our tran- charge along the one-dimensional nanotubes. (FETs) on the same chip (Fig. 1C). sistors, a change in the output by more than 1 V Our nanotube transistors have a local gate Our nanotube circuits are realized in a three- occurs when the input voltage is changed by 0.1 that is insulated from the nanotube by a gate step process. First, Al gates are patterned using V. This indicates a large-signal gain Ͼ10. A oxide layer of only a few nanometers thickness. electron beam lithography (18) on an oxidized large gain combined with a large output In previous circuits, the gate consisted of an Si wafer. The insulating layer consists of the swing can be obtained because the gate is so native oxide that grows by exposing the sample close to the nanotube. Our technique allows to air. The precise thickness of this layer is for a much larger gain than has been achieved Department of Applied Physics, Delft University of Tech- difficult to determine, but is on the order of a with thick gate oxides or planar gates used in nology, Lorentzweg 1, 2628 CJ Delft, Netherlands. few nanometers (19). Second, single-wall car- previous nanotube FETs (6, 7, 9, 23). *Present address: Laboratoire de Physique de la Ma- bon nanotubes produced by laser ablation are A major point of our report is that small « tie`re Condense«e, Ecole Normale Superieure, 24 Rue dispersed on the wafer from a dichloroethane circuits combining our nanotube transistors can Lhomond, 75005 Paris, France. †To whom correspondence should be addressed. E- suspension. With an atomic force microscope, be used for a variety of logic elements. Here, we mail: [email protected] those nanotubes are selected that have a diame- describe our demonstration of an inverter, a www.sciencemag.org SCIENCE VOL 294 9 NOVEMBER 2001 1317 R EPORTS -7 A 100nm Al 10 -1.0 V 0 -8 10 -1.1 V SiO2 Au -1.2 V -9 -20 ) 10 (nA) nanotube A I ( I -10 10 -40 -11 Vg = -1.3 V 10 A -60 -12 -1 -0.5 0 10 -44-20 2 B Vsd (V) V Vg (V) sd Al2O3 I Fig. 3. Device characteristics of the nanotube nanotube 4 V transistor. Typical I-V curves measured at Au Al g sd room temperature for various values of Vg.In SiO2 2 the linear regime at small source-drain volt- ) ages, the current is proportional to Vsd.Inthe C Au µ saturation regime at higher source-drain Al 1 m atom / e voltages (that is, when V becomes more 0 sd -2 negative than Vg Ð Vt), the current through 10 ( the transistor changes more gradually. For a e g constant Vsd in the saturation regime, I(Vg) -2 has an approximately parabolic dependence har 2 C ϳ I (Vg Ð Vt) , as is typical for MOSFETs. The B data are for a different transistor than in Fig. -4 2. Lines are guides to the eye. Large gain Fig. 1. Device layout. (A) Height image of a 0 20 40 60 (Ͼ10) is obtained. single-nanotube transistor, acquired with an Distance from the interface (nm) atomic force microscope. (B) Schematic side Fig. 2. Strong doping and weak screening of view of the device.
Load more

Recommended publications
  • Kavli-Maart 2014 V2.Indd
    KAVLI NEWSLETTER No.09 Kavli Institute of Nanoscience Delft March 2014 IN THIS ISSUE: How we became a Kavli Institute • 10 years of Kavli Delft • Kavli Colloquium Hongkun Park Introduction new faculty: Marileen Dogterom and Greg Bokinsky FROM THE DIRECTOR Philanthropist Fred A full newsletter again this month! First, our frontpage news that our benefactor Fred Kavli passed away. Kavli passed away I very well remember when I met him for the fi rst time, in 2003: Fred was a soft spoken and kind man, with a strong determination to use his busi- ness-generated fortune to advance science for the benefi t of humanity by supporting scientists and their work. Throughout the years I inter- acted with him a number of times, where this fi rst impression was re- confi rmed time and again. Now he has passed away. We will miss him, and continue the nanoscien- ce at Delft that he has supported so generously. Also, this month, we celebrate our 10-year birthday as a Kavli Insti- tute. For this occasion, Hans Mooij recalls the history of the start of our institute - a very interesting story in- deed, read it on page 6-7. Finally, this newsletter features our Kavli Colloquium speaker Hongkun Park, introductory self-interviews by Marileen Dogterom and Greg On 21 November 2013, the Kavli Foundation announced that its Bokinsky, wonderful columns, and more. founder Fred Kavli has passed away peacefully in his home in Santa Enjoy! Barbara at the age of 86. As philanthropist, physicist, entrepreneur, • Cees Dekker business leader and innovator, Fred Kavli established The Kavli Foun- dation to advance science for the benefi t of humanity.
    [Show full text]
  • Carbon Nanotube Biosensors: the Critical Role of the Reference Electrode ͒ Ethan D
    APPLIED PHYSICS LETTERS 91, 093507 ͑2007͒ Carbon nanotube biosensors: The critical role of the reference electrode ͒ Ethan D. Minot,a Anne M. Janssens, and Iddo Heller Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands Hendrik A. Heering Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands Cees Dekker and Serge G. Lemay Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands ͑Received 30 May 2007; accepted 1 August 2007; published online 28 August 2007͒ Carbon nanotube transistors show tremendous potential for electronic detection of biomolecules in solution. However, the nature and magnitude of the sensing signal upon molecular adsorption have so far remained controversial. Here, the authors show that the choice of the reference electrode is critical and resolves much of the previous controversy. The authors eliminate artifacts related to the reference electrode by using a well-defined reference electrode to accurately control the solution potential. Upon addition of bovine serum albumin proteins, the authors measure a transistor threshold shift of −15 mV which can be unambiguously attributed to the adsorption of biomolecules in the vicinity of the nanotube. © 2007 American Institute of Physics. ͓DOI: 10.1063/1.2775090͔ Biosensors based on nanoscale field-effect transistors determining redox couple.13 Sensors for biomolecule binding have the potential to significantly impact drug discovery, dis- are generally operated in buffer solutions where the redox ease screening, biohazard screening, and fundamental species are not controlled and the background redox reac- 1 science.
    [Show full text]
  • Nanofabricated Structures and Microfluidic Devices for Bacteria: from Techniques to Biology Cite This: DOI: 10.1039/C5cs00514k Fabai Wu and Cees Dekker*
    Chem Soc Rev View Article Online TUTORIAL REVIEW View Journal Nanofabricated structures and microfluidic devices for bacteria: from techniques to biology Cite this: DOI: 10.1039/c5cs00514k Fabai Wu and Cees Dekker* Nanofabricated structures and microfluidic technologies are increasingly being used to study bacteria because of their precise spatial and temporal control. They have facilitated studying many long-standing questions regarding growth, chemotaxis and cell-fate switching, and opened up new areas such as probing the effect of boundary geometries on the subcellular structure and social behavior of bacteria. Received 30th June 2015 We review the use of nano/microfabricated structures that spatially separate bacteria for quantitative DOI: 10.1039/c5cs00514k analyses and that provide topological constraints on their growth and chemical communications. These approaches are becoming modular and broadly applicable, and show a strong potential for dissecting www.rsc.org/chemsocrev the complex life of bacteria at various scales and engineering synthetic microbial societies. Key learning points (1) Microfabricated structures can spatially isolate and separate bacteria for single-cell analyses, for drug discovery by cultivating natural species on chips, and for lineage tracking that reveals the rules governing cell growth, cell-fate decisions, and antibiotic resistance. (2) Microfluidic devices that separate bacteria with semipermeable materials allow dissecting the effect of chemical communication between bacteria that exchange metabolic
    [Show full text]
  • Simultaneous Electrical Transport and Scanning Tunneling Spectroscopy
    NANO LETTERS xxxx Simultaneous Electrical Transport and Vol. 0, No. 0 Scanning Tunneling Spectroscopy of A-E Carbon Nanotubes Brian J. LeRoy,*,† Iddo Heller, Vijay K. Pahilwani, Cees Dekker, and Serge G. Lemay KaVli Institute of Nanoscience, Delft UniVersity of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands Received April 5, 2007; Revised Manuscript Received May 22, 2007 ABSTRACT We performed scanning tunneling spectroscopy measurements on suspended single-walled carbon nanotubes with independently addressable source and drain electrodes in the Coulomb blockade regime. This three-terminal configuration allows the resistance to the source and drain electrodes to be individually measured, which we exploit to demonstrate that electrons were added to spin-degenerate states of the carbon nanotube. Unexpectedly, the Coulomb peaks also showed a strong spatial dependence. By performing simultaneous scanning tunneling spectroscopy and electrical transport measurements we show that the probed states are extended between the source and drain electrodes. This indicates that the observed spatial dependence reflects a modulation of the contact resistance. Single-walled carbon nanotubes (SWCNTs) have extremely growing SWCNTs directly on Pt electrodes separated by a promising electrical transport properties. In a field-effect trench.10 A 100 nm trench was etched in a Si wafer with a transistor geometry, they have been shown to have a higher 250 nm SiO2 layer to create the separation between the two drive current and transconductance than can be found in Si Pt electrodes which were used as the source and drain devices.1 However, one of the major unresolved issues is electrode. 8 µm × 5 µm regions were defined by electron- the influence of the contacts on their transport properties.2-4 beam lithography at a distance of 1.5 µm from the trench.
    [Show full text]
  • Nanotechnology in the EU – Bioanalytical and Biodiagnostic Techniques
    Nanotechnology in the EU – Bioanalytical and Biodiagnostic Techniques. September 2004 1 Nanotechnology in the EU – Bioanalytical and Biodiagnostic Techniques A Nanoforum report, available for download from www.nanoforum.org. Author Christof Ruch Editor Mark Morrison 2 Nanotechnology in the EU – Bioanalytical and Biodiagnostic Techniques Nanotechnology in the EU – Bioanalytical and Biodiagnostic Techniques ...... 2 1 Object of this report ...................................................................... 5 2 About Nanoforum.......................................................................... 6 2.1 What is nanotechnology? ............................................................. 7 2.2 Present and future of nanotechnology in diagnostics and analytics ..... 7 2.3 Key techniques and equipment ..................................................... 9 2.3.1 Arrays/biochips .................................................................... 9 2.3.2 Lab-on-a-chip .................................................................... 12 2.3.3 Imaging ............................................................................ 13 2.3.4 Metrology .......................................................................... 15 2.3.4.1 Scanning Probe Microscopes........................................... 15 2.3.4.2 Quantum Dots.............................................................. 16 2.3.4.3 Surface Plasmon Resonance ........................................... 18 3 European Initiatives ...................................................................
    [Show full text]
  • Curriculum Vitae Derek Stein
    Curriculum Vitae Derek Stein 1. NAME, POSITION, AND DEPARTMENT Derek Stein Associate Professor Department of Physics and School of Engineering 2. WORK ADDRESS 182 Hope Street Providence, RI, 02912 USA 3. EDUCATION Ph.D. (Applied Physics) Harvard University, 2003 Dissertation topic: Ion Beam Sculpting Molecular-Scale Devices M.Sc. (Applied Physics) Harvard University, 1998 B.Sc. (Physics, Honours) McGill University, 1997 B.Sc. Candidate (Physics) Queen’s University (Canada), 1993 – 1994 4. PROFESSIONAL APPOINTMENTS 2014 – present Brown University, Department of Physics and School of Engineering Associate Professor 2014 Ecole Normale Superieure de Paris, Laboratoire de Physique Statistique Visiting Professor 2013 – 2014 Brown University, Department of Physics Associate Professor 2011 – 2013 Brown University, Department of Physics Manning Assistant Professor 2006 – 2011 Brown University, Department of Physics Assistant Professor 2003 – 2006 Delft University of Technology, Kavli Institute of Nanoscience Postdoctoral research in the group of Cees Dekker 2002 Agilent Technologies, Life Sciences Technologies Laboratory Nanopore technology transfer from Ph.D. research 1998 – 2002 Harvard University, Division of Engineering and Applied Sciences Research Fellow in the group of Jene Golovchenko 1993 – 1997 Merck-Frosst Canada, Pharmaceutical Research and Development Summer research projects 5. COMPLETED PUBLICATIONS b. Chapters in books 1. “Ion, Polymer, and Biomolecule Transport in the Nanofluidic Regime”, Derek Stein, Mar- tin van den Heuvel and Cees Dekker, in: Nanofluidics: Nanoscience and Nanotechnology, Joshua Edel and Andrew de Melo, Eds. Royal Society of Chemistry, London, (2009). 2. “Passive and Electrically Actuated Solid-State Nanopores for Sensing and Manipulating DNA”, Zhijun Jiang, Mirna Mihovilovic, Erin Teich, and Derek Stein, in: Nanopore-based technology: Single molecule characterization and DNA sequencing, M.E.
    [Show full text]
  • Forcing DNA and RNA Through Artificial Nanopores
    Forcing DNA and RNA through Artificial Nanopores Proefschrift ter verkrijging van de graad van doctor aan de Technische Universiteit Delft; op gezag van de Rector Magnificus prof. ir. K.C.A.M. Luyben, voorzitter van het College voor Promoties, in het openbaar te verdedigen op donderdag 21 oktober 2010 om 15.00 uur door Michiel VAN DEN HOUT doctorandus in de natuurkunde geboren te Leiderdorp. Dit proefschrift is goedgekeurd door de promotor: Prof. dr. N.H. Dekker Samenstelling van de promotiecommissie: Rector Magnificus Voorzitter Prof. dr. N.H. Dekker Technische Universiteit Delft, promotor Prof. dr. U. Gerland München, Germany Prof. dr. G.T. Barkema Universiteit Leiden Prof. dr. C. Dekker Technische Universiteit Delft Prof. dr. H.W. Zandbergen Technische Universiteit Delft Dr. U.F. Keyser Cambridge University, United Kingdom Dr. D. Stein Brown University, Verenigde Staten Keywords: RNA, DNA, nanopores, optical tweezers, single molecule, nanotechnology, electrophoresis Published by: Michiel van den Hout Cover design: Kasper van den Hout Printed by: Off Page The production of this thesis was financially supported by Delft University of Technology and J. van den Hout Beheer B.V. An electronic version of this dissertation is available at: http://www.library.tudelft.nl/dissertations/ Copyright © 2010 by Michiel van den Hout Casimir PhD series, Delft‐Leiden, 2010‐26 ISBN: 978‐90‐8593‐085‐3 Whatever you do will be insignificant, but it is very important that you do it Mahatma Gandhi Preface This is it. And this it can mean a lot of things. First, it refers to this preface, the only part of this book that most of its owners will actually read.
    [Show full text]
  • Identifying the Mechanism of Biosensing With
    NANO LETTERS 2008 Identifying the Mechanism of Vol. 8, No. 2 Biosensing with Carbon Nanotube 591-595 Transistors Iddo Heller, Anne M. Janssens, Jaan Ma1nnik, Ethan D. Minot,† Serge G. Lemay, and Cees Dekker* KaVli Institute of Nanoscience, Delft UniVersity of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands Received November 16, 2007; Revised Manuscript Received December 1, 2007 ABSTRACT Carbon nanotube transistors have outstanding potential for electronic detection of biomolecules in solution. The physical mechanism underlying sensing however remains controversial, which hampers full exploitation of these promising nanosensors. Previously suggested mechanisms are electrostatic gating, changes in gate coupling, carrier mobility changes, and Schottky barrier effects. We argue that each mechanism has its characteristic effect on the liquid gate potential dependence of the device conductance. By studying both the electron and hole conduction, the sensing mechanisms can be unambiguously identified. From extensive protein-adsorption experiments on such devices, we find that electrostatic gating and Schottky barrier effects are the two relevant mechanisms, with electrostatic gating being most reproducible. If the contact region is passivated, sensing is shown to be dominated by electrostatic gating, which demonstrates that the sensitive part of a nanotube transistor is not limited to the contact region, as previously suggested. Such a layout provides a reliable platform for biosensing with nanotubes. Nanoscale semiconducting materials
    [Show full text]
  • Cees Dekker, Curriculum Vitae
    Cees Dekker, Curriculum Vitae Personal data Full name Cornelis Dekker CV last updated 04-08-2021 Date and place of birth 7 april 1959, Haren, The Netherlands Nationality Netherlands Marital status Married, 3 children Address Delft University of Technology Kavli Institute of NanoScience Delft Department of Bionanoscience Van der Maasweg 9, 2629 HZ Delft, The Netherlands phone +31 - 15 - 2786094 website: https://ceesdekkerlab.nl e-mail: c.dekker @ tudelft.nl Education • 1977-1983 Experimental Physics at the University of Utrecht • 1984-1988 Ph.D. in Physics from University of Utrecht; thesis "Two-dimensional spin glasses" Academic appointments • 1984-1988 Research assistant at the University of Utrecht • 1988-1993 Assistant professor at the University of Utrecht • 1990-1991 Visiting researcher at IBM Research, Yorktown Heights, USA • 1993-1999 Associate professor at Delft University of Technology • Since 1999 Antoni van Leeuwenhoek full professor at Delft University of Technology. • 2000 Visiting researcher at Technion – Israel Institute of Technology, Haifa, Israel • Since 2000 Full professor of Molecular Biophysics, Delft University of Technology • 2001-2010 Group leader of the Molecular Biophysics group • Since 2006 Distinguished University Professor, Delft University of Technology • 2010-2013 Founding Chair of a new Department of Bionanoscience, TU Delft • 2010-2018 Director of the Kavli Institute of Nanoscience Delft • 2015-2020 Royal Academy Professor of the Royal Netherlands Academy of Arts and Sciences (KNAW) Curriculum Vitae C. Dekker Research overview • 1981-1983 Undergraduate research projects in medical physics (visual system) and solid-state physics (NMR and Monte Carlo simulations in dilute magnetic systems). • 1984-1988 Graduate research on low-dimensional spin glasses.
    [Show full text]
  • Microfluidic and Nanofabrication Tools to Study Bacteria Felix J
    Zooming in to see the bigger picture: Microfluidic and nanofabrication tools to study bacteria Felix J. H. Hol and Cees Dekker Science 346, (2014); DOI: 10.1126/science.1251821 This copy is for your personal, non-commercial use only. If you wish to distribute this article to others, you can order high-quality copies for your colleagues, clients, or customers by clicking here. Permission to republish or repurpose articles or portions of articles can be obtained by following the guidelines here. The following resources related to this article are available online at www.sciencemag.org (this information is current as of October 23, 2014 ): Updated information and services, including high-resolution figures, can be found in the online version of this article at: http://www.sciencemag.org/content/346/6208/1251821.full.html This article cites 112 articles, 48 of which can be accessed free: http://www.sciencemag.org/content/346/6208/1251821.full.html#ref-list-1 This article appears in the following subject collections: on October 23, 2014 Techniques http://www.sciencemag.org/cgi/collection/techniques www.sciencemag.org Downloaded from Science (print ISSN 0036-8075; online ISSN 1095-9203) is published weekly, except the last week in December, by the American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. Copyright 2014 by the American Association for the Advancement of Science; all rights reserved. The title Science is a registered trademark of AAAS. RESEARCH ecosystems in which the spatial eco-evo- REVIEW SUMMARY lutionary dynamics of bacterial communi- ties can be explored.
    [Show full text]
  • Room-Temperature Transistor Based on A
    letters to nature 9. Reichlin, R. et al. Evidence for the insulator-metal transition in xenon from optical, x-ray and band difficulties in achieving electrical contact to individual molecules. structure studies to 170 GPa. Phys. Rev. Lett. 62, 669–672 (1989). 10. Goettel, K. A., Eggert, J. H. & Silvera, I. F. Optical evidence for the metallization of xenon at 132 Recent advances in nanotechnology, however, have resulted in (5) GPa. Phys. Rev. Lett. 62, 665–672 (1989). electrical measurements on single molecules4–7. Here we report 11. Luo, H., Desgreniers, S., Vohra, Y. K. & Ruoff, A. L. High pressure optical studies on sulfur to 121 GPa: optical evidence for metallization. Phys. Rev. Lett. 67, 2998–3001 (1991). the fabrication of a field-effect transistor—a three-terminal 8–10 12. Desgreniers, S., Vohra, Y. K. & Ruoff, A. L. Optical response of very high density solid oxygen to switching device—that consists of one semiconducting 132 GPa. J. Phys. Chem. 94, 1117–1122 (1990). single-wall carbon nanotube11,12 connected to two metal electrodes. 13. Jayaraman, A. Diamond anvil cell and high pressure physical investigations. Rev. Mod. Phys. 55, 65– 108 (1983). By applying a voltage to a gate electrode, the nanotube can be 14. Kawai, N., Togaya, M. & Mishima, O. A study of the metallic hydrogen. Proc. Japan Acad. 51, 630–633 switched from a conducting to an insulating state. We have (1975). previously reported5 similar behaviour for a metallic single-wall 15. Vereshchagin, L. F., Yakovlev, E. N. & Timofeev, Yu A. Possibility of transition of hydrogen into the 8 metallic state.
    [Show full text]
  • Room-Temperature Transistor Based on a Single
    letters to nature 9. Reichlin, R. et al. Evidence for the insulator-metal transition in xenon from optical, x-ray and band difficulties in achieving electrical contact to individual molecules. structure studies to 170 GPa. Phys. Rev. Lett. 62, 669–672 (1989). 10. Goettel, K. A., Eggert, J. H. & Silvera, I. F. Optical evidence for the metallization of xenon at 132 Recent advances in nanotechnology, however, have resulted in (5) GPa. Phys. Rev. Lett. 62, 665–672 (1989). electrical measurements on single molecules4–7. Here we report 11. Luo, H., Desgreniers, S., Vohra, Y. K. & Ruoff, A. L. High pressure optical studies on sulfur to 121 GPa: optical evidence for metallization. Phys. Rev. Lett. 67, 2998–3001 (1991). the fabrication of a field-effect transistor—a three-terminal 8–10 12. Desgreniers, S., Vohra, Y. K. & Ruoff, A. L. Optical response of very high density solid oxygen to switching device—that consists of one semiconducting 132 GPa. J. Phys. Chem. 94, 1117–1122 (1990). single-wall carbon nanotube11,12 connected to two metal electrodes. 13. Jayaraman, A. Diamond anvil cell and high pressure physical investigations. Rev. Mod. Phys. 55, 65– 108 (1983). By applying a voltage to a gate electrode, the nanotube can be 14. Kawai, N., Togaya, M. & Mishima, O. A study of the metallic hydrogen. Proc. Japan Acad. 51, 630–633 switched from a conducting to an insulating state. We have (1975). previously reported5 similar behaviour for a metallic single-wall 15. Vereshchagin, L. F., Yakovlev, E. N. & Timofeev, Yu A. Possibility of transition of hydrogen into the 8 metallic state.
    [Show full text]