Original Publication Date
Physical Review B
DOI of Original Publication
Date of Submission
We calculate the terahertz absorption spectra associated with intersubband transitions in a semiconductor quantum wire in the presence of spin-orbit interaction and a transverse magnetic field. The frequencies and intensities of the absorption peaks are found to depend strongly on the spin-orbit coupling strength, which can be varied with an external electric field. This feature can be exploited to realize reconfigurable multispectral terahertz detectors and amplitude and/or frequency modulators. We also show that electric dipole transitions between spin-split levels in the same subband (which are normally deemed forbidden) become allowed because of spin texturing effects. The absorption associated with these transitions experience a redshift (blueshift) with increasing spin-orbit coupling strength for materials with negative (positive) g factor. The normally allowed transitions, on the other hand, experience the opposite shift, i.e., blue for materials with negative g factor and red for materials with positive g factor. The theory described here is universal and applies to all semiconductors.
Upadhyaya, P., Pramanik, S., and Bandyopadhyay, S. Optical transitions in a quantum wire with spin-orbit interaction and its applications in terahertz electronics: Beyond zeroth-order theory. Physical Review B, 77, 155439 (2008). Copyright © 2008 American Physical Society.
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VCU Electrical and Computer Engineering Publications