Findings may prove useful in search for elusive Majorana
quasiparticle
Topological insulators (TIs) are an exciting new type of
material that on their surface carry electric current, but within their bulk,
act as insulators. Since the discovery of TIs about a decade ago, their unique
characteristics (which point to potential applications in quantum computing)
have been explored theoretically, and in the last five years, experimentally.
But where in theory, the bulk of TIs carry no current, in
the laboratory, impurities and disorder in real materials mean that the bulk
is, in fact, conductive. This has proven an obstacle to experimentation with
TIs: findings from prior experiments designed to test the surface conductivity
of TIs unavoidably included contributions from the surplus of electrons in the
bulk.