Abstract
By combining transport and photoemission measurements on thin films, we report that this system transforms from a topologically nontrivial metal into a topologically trivial band insulator through three quantum phase transitions. At , there is a transition from a topologically nontrivial metal to a trivial metal. At , the metal becomes a variable-range-hopping insulator. Finally, above , the system becomes a true band insulator with its resistance immeasurably large even at room temperature. This material provides a new venue to investigate topologically tunable physics and devices with seamless gating or tunneling insulators.
- Received 26 April 2012
DOI:https://doi.org/10.1103/PhysRevLett.109.186403
© 2012 American Physical Society