Study On Magnetic Transport Characteristics Of Si - Si Nanowire Array

In-plane GeSi nanowire arrays were fabricated by molecular beam epitaxy (MBE) method on the vicinal Si (001) substrates～8°toward the<110>. Aluminum electrodes were deposited on the GeSi nanowire array sample surface and annealed, and the magneto-transport property, in the directions of both along the nanowires and perpendicular to the nanowires, was studied through the four-probe method in the Physical Property Measurement System (PPMS). An asymmetrical MR versus B was observed with a minimum MR at Bmin≠0was found in the measurements made in both directions mentioned above, and the Bmin increases as the temperature increased.Based on the spin-orbit coupling and the Zeeman effect, we made an explain for the phenomena. We propose that the asymmetrical MR curve is caused by Zeeman Effect and Spin-Orbit Effect:the concentration of carriers with different spin directions is modified by external magnetic field through the Zeeman effect, and in GeSi nanowires array system, the carrier mobility of the different spin directions differs due to spin-orbit coupling. We found that this theory is very consistent with the experimental results, and by fitting the data, mobility difference between carriers with different spin directions is caculated. The maximum value of the difference reached up to approximately26%. We found that the difference of the carrier mobility of the different spin directions increases with the rise in temperature within the range from50K-80K, but decreases as the temperature changes from80K to300K.