Transport in semiconductor nanostructures: topological insulators and spin hall effect in HgTe

• Grant number: 11/19441-1
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: February 01, 2012
• End date: March 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Gennady Gusev
• Grantee: Gennady Gusev
• Visiting researcher: Olshanetsky Evgenii
• Visiting researcher institution: Russian Academy of Sciences (RAS), Russia
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The visit of Dr. E. B. Olshanetsky will be very useful to continue the long-term collaboration between Novosibirsk and New Semiconductor Materials Laboratory of the Institute of Physics, University of São Paulo (LNMS-IFUSP). As leader of the LNMS IFUSP, I have developed several major projects, including the international-COFECUB USP, FAPESP and CNPq-CNRS-CIAM. The project's overall objective is to study of semiconductor nanostructures for the design of new quantum devices. During his last visit (FAPESP Process No.: 2008/09212-2) Dr. E. B. Olshanetsky measures performed on various types of quantum wells of CdTe / HgTe / CdTe carriers containing both electrons and holes simultaneously. The samples used were grown at the Institute of Semiconductor Physics in Novosribirsk, Russia. The study is focused mainly on the regime of quantum Hall effect near the point of neutrality of charge in the presence of strong magnetic fields. Three papers have been published (among them 1 1 Physical Review Letters and Physical Review B, Rapid Communications) involving the use of these samples [Ref.1-3], and several studies are under preparation. We propose the study of transport properties in HgTe quantum wells that is related to quantum spin Hall effect and topological insulator. The recent discovery of topological insulators, like other advances in basic condensed matter physics, enables new applications that exploit our new knowledge. The insulating properties of these surfaces can lead to new spintronic devices or magnetic. Moreover, in combination with superconductors, topological insulators can lead to new quantum computer architecture with bit which has topological properties. These insulators have had a considerable impact on condensed matter physics, making it clear that the topological effects which are intended only for low temperatures and high magnetic fields can determine the physical materials of macroscopic systems under ambient conditions. Our research points towards a new generation of electronic devices based on quantum mechanics. The discussion of physical problems and technological issues related to the manufacture of such systems in IFUSP and other laboratories and the measures to be carried in-LNMS IFUSP may accelerate the development of nanoelectronics in Brazil. (AU)