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James R. Heath
Department of Chemistry & Biochemistry, UCLA

Professor

BSc, Baylor University; PhD, Rice University;

Raymond and Beverly Sackler Prize in the Physical Sciences (2001); Rohm&Haas Lecturer, Univ. North Carolina (2001); Feynman Prize in Nanotechnology (2000); Jules Springer Prize for Applied Physics (2000); Fellow of the American Physical Society (1999); Hascoe Lecturer, Physics Dept. Univ. of Conn. (1999); Vanity Fair Magazine Hall of Fame (1999); Seaborg Award (1997); Sloan Fellowship (1997); Packard Fellowship (1994); NSF-NYI Award (1994); Miller Fellowship (1988); Rice Univ. Graduate Award for the Discovery of C60, the fullerenes, and La @ C60 (1987).

 
Research

We are interested in understanding how to fabricate, assemble, and utilize nanometer scale structures. We work on a diverse set of problems, and consequently we have extensive collaborations with other groups at UCLA, at other campuses, and with industrial research groups. For a more detailed look at my group, click on the photograph at the bottom of the page, and you will be directed to my group’s full web page. One of our goals is to learn how to use chemically synthesized quantum dots as “artificial atoms,” and how to control the properties of the solids that we get when we assemble these “atoms” into a superlattice. At the heart of this project is the notion that really only three physical parameters go in to determining the electronic properties of a crystal: the energy levels of the atoms (lattice sites); the coupling between adjacent sites; and the symmetry of the solid. Imagine being able to control each of these properties separately, and therefore being able to ‘design’ a solid with a prescribed set of electronic properties! For an atomic solid, this would amount to being able to tune the electronegativity of a given atom; being able to control the strength of the covalent interactions within the lattice; and, being able to choose the crystal structure. While the chemistry of the periodic table does not lend itself to such control, the chemistry of “artificial atoms” does. Over the past couple of years we have demonstrated that it is possible to design solids from quantum dots that have properties that, while predictable, are completely different from anything that can be synthesized in the traditional sense. A recent highlight of that work was our demonstration that we could intentionally design a quantum dot-based solid that could be reversibly switched between a metal and an insulator under ambient conditions. For this metal/insulator system, we had to learn how to carry out experiments in which covalent bonding was actually a continuously variable experimental parameter. Our current work in this area involves trying to design unique superconducting solids, and unique magnetic solids. For the superconducting and ferromagnetic systems, Josephson exchange coupling, and ferromagnetic exchange coupling, respectively, are the quantum mechanical analogues to covalent bonding.

A second project going on in my group involves trying to learn how to chemically synthesize a computer. Our ultimate goal is to build a computer with approximately the power of 100 high-end workstations on a platform the size of a grain of sand. This project, which is a collaboration between my group, Frasier Stoddart’s group, Hewlett Packard Corp., and UC Berkeley, has progressed very fast over the past year. What once seemed like science fiction is now looking more and more like science! We have developed a realistic computer architecture for nearly the entire machine, and we have recently demonstrated electronically configurable molecular-based logic circuitry. We hope that, within the next couple of years, we will have developed molecular based memories and molecular-based communications networks. Some of the highlights of this work are also listed on the group web page.

Finally, the third project is aimed at understanding the nano-circuitry of biological systems. We are developing a scanning nonlinear optical microscope which will allow us to non-invasively probe, at high spatial resolution, biological electrical functions such as ion-channel switching. This microscope will have the power to resolve molecular identities and orientations at the 0.1 micron length scale. This project is a collaboration with the UCLA medical school, and with Rich Saykally at UC Berkeley. This is a young project, and clearly represents a long-term research commitment. Some of our initial successes in the form of nonlinear optical micrograph images have been placed on the group web page.

Representative Publications

  1. J.R. Heath, C.M. Knobler, and D.V. Leff,Pressure/Temperature Phase Diagrams and Superlattices of Organically Functionalized Metal Nanocrystal Monolayers: The Influence of Particle Size, Size Distribution, and Surface Passivant, J. Phys. Chem.B 101, 198 (1997).

  2. P. Ohara, W.M. Gelbart, and J.R. Heath,Selft-Assembly of Sub-Micrometer Rings of Particles From Solutions of Nanoparticles, Ang. Chem. Comm. Int. Ed. Engl. 36, 1078 (1997).

  3. J.J. Shian, R. H. Wolters, and J.R. Heath,Theory of Size-Dependent Resonance Raman Intensities in InP Nanocrystals, J. Chem. Phys., 106, 8981 (1997).

  4. T. Vossmeyer, E. DeIonno, and J.R. Heath, Light-directed Assembly of Nanoparticles, Angew. Chemie Comm. Int. Ed. Engl. 36, 1080 (1997).

  5. G. Markovich, et al., Parallel Fabrication and Single-Electron Charging of Devices based on Ordered, Two-Dimensional Phases of Organically-Functionalized Metal Nanocrystals, Appl. Phys. Lett. 70, 3107 (1997).

  6. C.P. Collier, S. Henrichs, J.J. Shiang, R.J. Saykally, and J.R. Heath, Reversible Tunning of Silver Quantum Dot Monolayers Through the Metal-Insulator Transition, Science, 277, 1978-80 (1997).

  7. J.R. Heath, P.J. Kuekes, G. Snider, and R.S. Williams, A Defect Tolerant Computer Architecture: Opportunities for Nanotechnology, Science, 280, 1716 (1998).

  8. G. Markovich, C.P. Collier, and J.R. Heath, Observation of a Reversible Metal-Insulator Transition in Ordered Metal Nanocrystal Monolayers by Impedence Spectroscopy, Phys. Rev. Lett., 80, 3807 (1998).

  9. C.P. Collier, T. Vossmeyer, J.R. Heath, Quantum Dot Superlattices, Ann. Rev. Phys. Chem. 49, 371 (1998).

  10. T. Vossmeyer, X. Jia, E. DeIonno, M. Diehl, X. Peng, A.P. Alivisatos, J.R. Heath, Combinatorial Approaches Toward Patterning Nanocrystals, J. Appl. Phys., 84, 3664 (1998).

  11. F. Remacle, C.P. Collier, G. Markovich, J.R. Heath, U. Banin, and R.D. Levine, Networks of Quantum Nano-Dots: The role of disorder in Modifying Electronic and Optiocal Properties, J. Phys. Chem. B, 102, 7727 (1998).

  12. S.H. Kim, G. Markovich, S. Rezvani, S.H. Choi, K.L. Wang, and J.R. Heath, Single-Electron Structure in MIS Tunnel Diodes Fabricated From CdSe Nanocrystal Monolayers, Applied Physics Letters, 74, 317 (1999).

  13. G. Madeiros-Ribeiro, D.A.A. Ohlberg, R.S. Williams, and J.R. Heath, Rehybridization of Electronic Structure in Compressed 2D Quantum Dot Superlattices, Phys. Rev. B (brief reports), 59, 1633 (1999).

  14. S. Henrichs, J. Sample, J. Shiang, C.P. Collier, R.J. Saykally, and J.R. Heath, Positive and Negative Contrast Lithography of Ag Nanocrystal Monolayers using a Scanning Non-linear Microscope, J. Phys. Chem. B (cover article) 103, 3524 (1999).

  15. G. Markovich, C.P. Collier, S. Henrichs, F. Remacle, R. Levine, and J.R. Heath, Architectonic Quantum Dot Solids, Acc. Chem. Res., 32, 415 (1999).

  16. R. P. Sear, S.-W. Chung, G. Markovich, W.M. Gelbart, and J.R. Heath, Spontaneous Patterning of Quantum Dots at the Air-Water Interface, Phys. Rev. E (rapid comm.), 59, R6255 (1999).

  17. C.P. Collier, E.W. Wong, M. Belohradsky, F.J. Raymo, J.F. Stoddart, P.J. Kuekes, R.S. Williams, and J.R. Heath, Electronically Configurable Molecular-Based Logic Gates, Science, 285, 391 (1999).

  18. E.W. Wong, C.P. Collier, M.Behloradský, F.M. Raymo, J.F. Stoddart, and J.R. Heath, Fabrication and Transport Properties of Single-Molecule Thick Electrochemical Junctions, J. Am. Chem. Soc. (in press 3/2000).

  19. S. Henrichs, C.P.Collier, R.J. Saykally, Y.R. Shen, and J.R. Heat, The Optical Dielectric Function of Ag Quantum Dot Monolayers Compressed through the Metal/Insulator Transition, accepted to J. Am.Chem.Soc. (to appear 5/2000).

  20. S.W. Chung, J. Yu, and James R. Heath, Si Nanowire Devices, Appl. Phys. Lett. (to appear 4/2000).

  21. I. Weitz, J. Sample, R. Ries, E. Spain, and J.R. Heath, Josephson Coupled Quantum Dot Artificial Solids J.Phys.Chem. B letter, (to appear 5/2000).
Contact Info

Department of Chemistry & Biochemistry
UCLA
Box 951569 (post)
607 Charles E. Young Drive East (courier)
Los Angeles, CA 90095-1569

Phone: (310) 825-2836
Fax: (310) 206-4038
Email: heath@chem.ucla.edu

Group

Heath Group Web Site


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