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Toward true topological insulator materials

Event Details

Event Dates: 

Friday, February 14, 2014 - 1:00pm

Seminar Location: 

  • Duane Physics Room D142

Speaker Name(s): 

Johnpierre Paglione

Speaker Affiliation(s): 

University of Maryland
Seminar Type/Subject

Scientific Seminar Type: 

  • Condensed Matter Seminar

Seminar Type Other: 

SPECIAL Condensed Matter Seminar

Event Details & Abstract: 

Bismuth selenide, regarded as the archetype topological insulator material, is in reality a good conducting metal with bulk carriers that derive from a self-doping caused by selenium vacancies. We report the synthesis of stoichiometric Bi2Se3 crystals that exhibit nonmetallic behavior in electrical transport down to low temperatures, providing the first indications of a truly insulating topological insulator material. I will discuss the peculiar presence of both electron- and hole-like carriers, along with the achievement of ambipolar transport in bulk Bi2Se3 crystals without gating techniques. In addition, new quantum transport studies of the proposed topological Kondo insulator samarium hexaboride will present our findings of a unique signature of non-trivial surface states.