Better surface Dirac states

Topological insulators are insulators that house gapless surface states. These states provide playground for a host of Dirac physics. Although a couple of such materials have been found, this newly examined one has some better features:

In summary, our ARPES experiment of TlBiSe2 has revealed three important aspects: First, the surface state Dirac cone is confirmed to be present at the Gamma point. Second, the Dirac cone is practically ideal, especially near the DP, and its velocity is larger than for Bi2Se3. Finally, according to both experiment and theory, there are no bulk continuum states that energetically overlap with the DP. This means that the scattering channel from the topological surface state to the bulk continuum is suppressed. Our experimental results favor the realization of the topological spin-polarized transport with high mobility and long spin lifetime in TlBiSe2. [PRL 105, 146801 (2010)]