| AVS 54th International Symposium | |
| Magnetic Interfaces and Nanostructures | Thursday Sessions |
| Session MI-ThM |
| Session: | Magnetic Semiconductors I |
| Presenter: | S.W. Cho, Seoul National University, Korea |
| Authors: | S.W. Cho, Seoul National University, Korea H.K. Choi, Seoul National University, Korea J.S. Lee, Seoul National University, Korea T. Hwang, Seoul National University, Korea Y.D. Park, Seoul National University, Korea |
| Correspondent: | Click to Email |
We report on the electrical transport measurements across clean lateral geometrical constrictions in diluted magnetic semiconductor GaMnAs. Constrictions are realized by e-beam lithography to define SiOx etch masks to pattern nanometer-sized constrictions without plasma etching processes. DC transport behavior across the nanoconstrictions changes from ohmic to non-ohmic below temperatures corresponding to epifilm TC. The nonlinear IV characteristics fit well with adapted transport equation accounting for spin-flop processes across the domain wall, analogous to pn junctions.1 Fits to theory also indicate the domain walls to be smooth and wide, inhospitable to tunneling transport, and supported by magnetoresistance behavior dominated by anisotropic magnetoresistance-like response similar to Giddings et al. observations.2 Extending the ‘spin diode’ concept of Vignale and Flatté,3 we conduct a series of dynamic measurements and observe a distinct two-level behavior dependent on bias conditions similar to certain behaviors found in bipolar junctions such as shot noise and random telegraph noise.
1G. Vignale and M.E. Flatté, PRL 89, 098302 (2002).
2A.D. Giddings et al., PRL 94, 127202 (2005).
3M.E. Flatté and G. Vignale, APL 78, 1273 (2001).