  The poor performance of copper interconnects at the nanometer scale calls for
new material solutions for continued scaling of integrated circuits. We propose
the use of three dimensional time-reversal-invariant topological insulators
(TIs), which host backscattering-protected surface states, for this purpose.
Using semiclassical methods, we demonstrate that nanoscale TI interconnects
have a resistance 1-3 orders of magnitude lower than copper interconnects and
graphene nanoribbons at the nanometer scale. We use the nonequilibrium Green
function (NEGF) formalism to measure the change in conductance of nanoscale TI
and metal interconnects caused by the presence of impurity disorder. We show
that metal interconnects suffer a resistance increase, relative to the clean
limit, in excess of 500% due to disorder while the TI's surface states increase
less than 35% in the same regime.
