Complex Open Systems Research Network

Dr David Campbell

 

Provost ad interim Boston University 2004-present. Dean, College of Engineering Boston University 2000-present. Address: College of Engineering Boston University 44 Cummington Street Boston, MA 02215 USA Phone: +1 617 353 2800 Fax: +1 617 353 5959 Email: dkcampbe@bu.edu Research Node: International

 

Role in Network

Academic - Researcher

COSNet Research Themes

1. Irreversibility and Emergence in Nonequilibrium Systems
2. Turbulence and Coherent Structures, Control and Computation
3. Dynamics and Statistics of Multi-Scale Systems
4. Network Theory
5. Cellular Automata, Agent-Based Modelling and Simulation

COSNet Application Areas

1. Complex Physical Systems
2. Complex Biological Systems
3. Complex Computational Systems
4. Complex Socio-Economic Systems

 

Research Topics

Nonlinear Dynamics of Electrons in Mesoscopic Nanostructures

Quantum dots, quantum wires, and heterojunction layers are of great interest for potential novel electronic devices. We studied the role of nonlinear dynamics in the transport of electrons through various mesoscopic nanostructures, including both vertical and lateral semiconductor superlattices and double-barrier resonance tunneling diodes focusing on effects created by the presence of external driving by both dc- and ac-electric and dc-magnetic fields. Our results include predicting (1) deterministic chaos in the electron current, which would appear experimentally as a substantial increase in the effective noise of the device and (2) symmetry-breaking (i.e., the development of a dc bias in response to a purely ac applied electric field or to a suitably aligned dc magnetic field). We are verifying these predictions through collaborations with several experimental groups.

Quasi-One-dimensional Correlated Electronic Materials

In recent years, increasing computing power and significant progress in numerical algorithms have brought true many-body computational methods to the point at which quantitatively accurate results can be obtained for one-dimensional (1-D) systems involving simultaneously strong electron-electron and electron-phonon interactions. At the same time, significant experimental advances have been made for quasi-1-D electronic materials, such as conjugated polymers, Bechgaard salts, and high Tc cuprate semiconductors, in terms of both materials synthesis and preparation and physical characterization and measurement. Our research, comparing the results of detailed numerical studies with experimental data, focuses on a systematic theoretical investigation of 1-D lattice many-body models, including the important Peierls-Hubbard and spin-Peirels models.

Many-Particle Tunneling Effects and Resonant Processes in Mesoscopic Systems

Remarkable recent advances in materials science permit the construction of new "mesoscopic/nanoscale" materials with structures on the scale of 10-100 nm. These "quantum dots," "wires," and "layers" exhibit many new physical phenomena as nonlinear, quantum, and finite-size effects combine and compete. We have initiated three theoretical studies in this area: (1) correlated electron models for quantum dots and wires; (2) resonant processes in weak and strong electromagnetic fields; and (3) ground states and phase transitions in discrete quantum 1-D and 2-D systems, including the role of many-particle tunneling effects, diffusion, and quantum fluctuations. We will compare our results with experiments and seek applications in the designs of novel electronic devices.
Our research, comparing the results of detailed numerical studies with experimental data, focuses on a systematic theoretical investigation of 1D lattice many-body models, including the important Peierls-Hubbard (PH) and spin-Peierls models.  

Publications

1. D.K. Campbell, "Nonlinear Science: From Paradigms to Practicalities," Los Alamos Science 15, 218-262 (1987); reprinted in From Cardinals to Chaos: Reflections on the Life and Legacy of Stanislaw Ulam (Cambridge University Press, 1989).
2. E.Y. Loh, Jr. and D.K. Campbell, "Optical Absorption in Extended Peierls-Hubbard Models," Synth. Met. 27, A499 (1988).
3. D.K. Campbell, J.T. Gammel, and E.Y. Loh, Jr., "Modeling Electron-Electron Interactions in Reduced-Dimensional Materials: Bond Charge Coulomb Repulsion and Dimerization in Peierls-Hubbard Models," Phys. Rev. B 42, 475-496 (1990).
4. S. Mazumdar, S. Ramasesha, R.T. Clay, and D.K. Campbell, "Theory of coexisting charge and spin-density waves in (TMTTF)2Br, (TMTSF)2PF6, and a -(BEDT-TTF)2MHg(SCN)4," Phys. Rev. Lett. 82, 1522-1525 (1999).
5. R.T. Clay, A.W. Sandvik, and D.K. Campbell, "Possible exotic phases in the one-dimensional extended Hubbard model," Phys. Rev. B 59, 4665-4679 (1999).
6. K.N. Alekseev, G.P. Berman, and D.K. Campbell, "Strange attractor in resonant tunneling, Phys. Rev. B 58, 3954-3962 (1998).
7. K.N. Alekseev, E.H. Cannon, J.C. McKinney, F.V. Kusmartsev, and D.K. Campbell, "Spontaneous dc current generation in a resistively shunted semiconductor superlattice driven by a terahertz field," Phys. Rev. Lett. 80, 2669-2672 (1998).
8. A.W. Sandvik, R.R.P. Singh, D.K. Campbell, "Quantum Monte Carlo in the interaction representation: application to a spin-Peierls model," Phys. Rev. B 56, 14510-14528 (1997).
9. G.P. Berman, F.N. Bulgakov, D.K. Campbell, and I.V. Krive, "Quantum nonlinear resonance and quantum chaos in Aharonov-Bohm oscillations in mesoscopic semiconductor rings," Phys. Rev. B 56, 10338-10354, (1997).
10. K.N. Alekseev, G.P. Berman, D.K. Campbell, E.H. Cannon, and M.C. Cargo, "Dissipative chaos in semiconductor superlattices" Phys. Rev. B 54, 10625-10636 (1996).  

Membership/Fellowship of Key Organisations

Editor-in-Chief, CHAOS, 1991-present
Divisional Associate Editor, Physical Review Letters, 1988-91
Fellow, American Physical Society, 1990
Fellow, American Association for the Advancement of Science, 1988  

Awards and Distinctions

Editor-in-Chief, CHAOS, 1991–present
Stanislaw Ulam Fellow, Los Alamos National Laboratory, 1998–99
Divisional Associate Editor, Physical Review Letters, 1988–91
Fellow, American Physical Society, 1990
Fellow, American Association for the Advancement of Science, 1988
Exchange Scientist to PROC Ministry of Education 1986
Visiting Professor, Univ. de Dijon, France, 1984 and 1985
NSF Predoctoral Fellowship, Cambridge University, 1968-70
Marshall Scholarship, Cambridge University, 1966-68