S. James Allen, received a Ph.D. degree in electrical engineering from M.I.T. in 1965.  He was appointed Professor of  Physics and Director of the Quantum Institute at UCSB in 1991, and recently served as Chair of Physics, 2000-05.  Prior to that, he had been a member of technical staff at Bell Labs, where he was recognized as a “Distinguished Member of Technical Staff”,  had availed himself of a Bell Labs supported leave at the Royal School of Mines , Imperial College London and later joined Bellcore, as District Research Manager of Solid State Physics Research.  He has also been an adjunct professor at Northeastern University and at Princeton University.   Professional service has included election as Member at Large of the Executive Committee of the Division of Condensed Matter Physics of the A.P.S. where he served on the Strategic Planning Committee and on the Nominating Committee.  He has also served on the Editorial Board of Physical Review.  In 1995 he won a Humboldt Science Award, is a Fellow of the American Physical Society and a Fellow of the American Association for the Advancement of Science.

 He has co-authored more than 200 publications on transport and terahertz excitations in semiconductor nano-structures, hot-electron dynamics, high temperature superconductivity, magnetism, superionic conductors, metal physics, clathrate inclusion compounds and protein dynamics. He holds three patents.  Current research focuses on terahertz dynamics in semiconductor quantum structures far from equilibrium, Bloch oscillators, novel plasmonic terahertz detectors, spin wave logic devices and terahertz dynamics of bio-polymers in solution.

Teaching related

Spring 2008: Physics 2, Basic Physics

Winter 2008: Physics123B, Condensed Matter Physics

Fall 2007: Physics 123A, Condensed Matter Physics

Current Research Efforts

Spin wave logic devices:                 All spin logic devices based on spin waves in ferromagnetic films patterned as interferometers, local magnetization controlled switching and scattering from spin torque devices.

Plasmonic terahertz detectors:         Voltage tuned plasmon resonances are exploited for narrow band terahertz detectors and are developed for terahertz spectroscopic focal plane arrays.

Terahertz emitters:                           Efforts here focus on turning the the phenomenon of Bloch oscillation into a terahertz Bloch oscillator.

Terahertz biopolymer dynamics:      Measuring the terahertz dynamics of proteins in solution by direct absorption spectroscopy and optical/terahertz sum and difference frequency generation in proteins in solution.

Selected recent publications

"Single-quantum-well grating-gated terahertz plasmon detectors", E. A. Shaner, Mark Lee, M. C. Wanke, A. D. Grine, J. L. Reno, S. J. Allen, Appl. Phys. Lett. 87, 193507 (2005).

"Far-Infrared Spectrum Analysis Using Plasmon Modes in a Quantum-Well Transistor", E. A. Shaner, A. D. Grine, M. C. Wanke, Mark Lee, J. L. Reno, and S. J. Allen, IEEE Phot. Tech. Lett., 18, 1925 (2006).

"0.15–3.72 THz absorption of aqueous salts and saline solutions", Jing Xu, Kevin W. Plaxco, S. James Allen, Jon E. Bjarnason, Elliott R. Brown, Appl. Phys.Lett. 90, 031908 (2007).

"Collective Dynamics of Lysozyme in Water: Terahertz Absorption Spectroscopy and Comparison with Theory", Jing Xu, Kevin W. Plaxco, and S. James Allen, J. Phys. Chem. B 2006, 110, 24255-24259.

"Probing the collective vibrational dynamics of a protein in liquid water by terahertz absorption spectroscopy", Jing Xu, Kevin W. Plaxco and S. James Allen, Protein Sci. 2006 15: 1175-1181.

"Absorption spectra of liquid water and aqueous buffers between 0.3 and 3.72 THz", Jing Xu, Kevin W. Plaxco and S.James Allen, J. Chem. Phys., 124, 036101 (2006).

“Loss and Gain in Bloch Oscillating Super-Superlattices: THz Stark Ladder Spectroscopy”, Peter Robrish, Jing Xu, Shigeki Kobayashi, Pavlos G. Savvidis, Borys Kolasa, Greg Lee, Dan Mars and S. James Allen, to be published, proceedings of MSS-12.  

“Bloch Oscillating Super-Superlattices”, P Robrish, J Xu, S Kobayashic, P G Savvidis, B Kolasa, G Lee, D Mars and S J Allen, to be published, proceedings NGS-12.

“Terahertz photoconductivity and plasmon modes in double-quantum-well field-effect transistors”, Peralta XG, Allen SJ, Wanke MC, Harff NE, Simmons JA, Lilly MP, Reno JL, Burke PJ, Eisenstein JP, App. Phys. Lett., 81, 1627 (2002).

“Magnetic anisotropy and interlayer coupling in Fe/sub 0.5/Co/sub 0.5/(100) films on GaAs(100)”, Pechan MJ, Compton RL, Bennett D, Chen LC, Palmstrom CJ, Allen SJ., J. of Appl. Phys., 89, 7514 (2001).

“Coherent transfer and electron teleportation in semiconductor double quantum well.”, Rufenacht M, Tsujino S, Allen SJ, Schoenfeld W, Petroff P, Phys. Stat. Solidi B-221, 407 (2000).

“Frequency doubling and tripling of terahertz radiation in a GaAs/AlAs superlattice due to frequency modulation of Bloch oscillations”, Winnerl S, Schomburg E, Brandl S, Kus O, Renk KF, Wanke MC, Allen SJ, Ignatov AA, Ustinov V, Zhukov A, Kop'ev PS, Appl. Phys. Lett., 77,1259 (2000).

“Quantum confinement without walls”, Tsujino S, Allen SJ, Thomas M, Eckhause T, Gwinn E, Rufenacht M, Zhang JP, Speck J, Sakaki H, Superlattices & Microstructures, 27, 469 (2000).

“Absorption of Terahertz Radiation by Plasmon Modes in a Grid-gated Double-Quantum-well Field-Effect Transistor,” V. V. Popov, X. G. Peralta, S. J. Allen, N. J. M. Noring, O. V. Polischuk, T. V. Teperik, and M. C. Wanke, J. Appl. Phys.  94, 3556 (2003).

“Terahertz Circular Dichroism Spectroscopy of Biomolecules”, Jing Xu, Jhenny Galan, Gerry Ramian, Pavlos Savvidis, Anthony Scopatz, Robert R, Birge, S. James Allen, Kevin Placo, to be published,  SPIE Proceedings, Vol. 5268, Conference on Chemical and Biological Standoff Detection.

“Resonant crossover of terahertz loss and gain in a Bloch oscillating InAs/AlSb super-superlattice.”, P.G. Savvidis, B. Kolasa, S.J. Allen, G. Lee, Phys. Rev. Lett., 92, 196802-1 (2004).

“Terahertz Circular Dichroism Spectroscopy:  A Potential Approach to Unbiased, in situ Life Detection,” J. Xu, G. J. Ramian, H. F. Galan, P. G. Savvidis, A. M. Scopatz, R. R. Birge, S. J. Allen, and K. W. Plaxco, Astrobiology, 3, 489-504 (2003) .

UCSB   Center for Terahertz Science and Technology

• Titles and abstracts of publications from the UCSB FEL's through   ~July 2004.

• FEL2004 Trieste, Advancing Terahertz Science and Technology with the UCSB Free-electron Lasers