A simple surface band structure and a large bulk band gap have allowed Bi2Se3 to become a reference material for the newly discovered three-dimensional topological insulators, which exhibit topologically protected conducting surface states that reside inside the bulk band gap. Studying topological insulators such as Bi2Se3 in nanostructures is advantageous because of the high surfaceto-volume ratio, which enhances effects from the surface states; recently reported Aharonov-Bohm oscillation in topological insulator nanoribbons by some of us is a good example. Theoretically, introducing magnetic impurities in topological insulators is predicted to open a small gap in the surface states by breaking time-reversal symmetry. Here, we present synthesis of magnetically doped Bi 2Se3 nanoribbons by vapor-liquid-solid growth using magnetic metal thin films as catalysts. Although the doping concentration is less than ∼2 %. low-temperature transport measurements of the Fe-doped Bi2Se3 nanoribbon devices show a clear Kondo effect at temperatures below 30 K, confirming the presence of magnetic impurities in the Bi2Se3 nanoribbons. The capability to dope topological insulator nanostructures magnetically opens up exciting opportunities for spintronics. © 2010 American Chemical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): S-11-001-12
Acknowledgements: This work was made possible by Support from the King Abdullah University of Science and Technology (KAUST) Investigator Award (No. KUS-11-001-12) and by an NSF-NRI Supplement to the Center for Probing the Nanoscale, an NSF Nanoscale Science and Engineering Center (PHY-0830228). D.G.-G. acknowledges support from the D. and L. Packard Foundation and the Hellman Faculty Scholar program. J.R.W. acknowledges support from the K. van Bibber Postdoctoral Fellowship of the Stanford Physics Department. A.J.B. acknowledges Support from in NDSEG Graduate Fellowship. P.G. acknowledges support from the Stanford Vice Provost for Undergraduate Education.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.