Strained HgTe: a textbook 3D topological insulator probed by magnetotransport
Laurent LEVY
Institut Néel
Mardi 17/01/2012, 15h00
Bât. K, Salle R. Lemaire (K223), Institut Néel

When growing HgTe on a CdTe substrate, bi-axial strain opens a gap in HgTe turning it from a semi metal into a topological insulator.  We have performed low field and high field magneto-transport in this 3D topological material.  We find that the bulk contribution to the transport current is much smaller than in any other known material.  A low field, we map the surface Dirac bands with a gated structure.
Antilocalization corrections to the conductivity have been observed and analyzed.  At high fields, there are 2 series of quantum Hall plateaus, one corresponds to a bilayer regime and the second to decoupled layers.
Experimental ways do identify the bilayer quantum Hall states are presently being pursued.

Contact : Michel BENINI

 

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