Abstract
We study ballistic transport of Dirac fermions in silicene through arrays of barriers, of width , in the presence of an exchange field and a tunable potential of height or depth . The spin- and valley-resolved conductances as functions of or , exhibit resonances away from the Dirac point (DP) and close to it a pronounced dip that becomes a gap when a critical electric field is applied. This gap widens by increasing the number of barriers and can be used to realize electric field-controlled switching of the current. The spin and valley polarizations of the current near the DP increase with or and can reach 100% for certain of their values. These field ranges widen significantly by increasing the number of barriers. Also, and oscillate nearly periodically with the separation between barriers or wells and can be inverted by reversing .
6 More- Received 13 September 2015
- Revised 27 October 2015
DOI:https://doi.org/10.1103/PhysRevB.92.195423
©2015 American Physical Society