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We provide a perspective on the recent emergence of “topological spintronics,” which relies on helical Dirac electrons on the surfaces of solids with strong spin-orbit coupling ..When timereversal symmetry is broken by ferromagnetic order, the helical Dirac states transition to chiral edge states . This is a realization of Haldane’s Chern insulator phase of matter, characterized by a precisely quantized Hall conductance and ballistic edge transport without a magnetic field, even in systems with significant electronic and magnetic disorder [3,4]. The interplay between these edge states, dissipative channels and magnetic order appears to yield a condensed matter realization of quantum tunneling out of a ‘false vacuum’ . Interesting opportunities are also emerging for patterning and manipulating the edge states using optical techniques . On a more pragmatic note, the helical spin texture of the surface states also leads to efficient spincharge conversion at room temperature [6,7], allowing one to envision novel devices for universal memory and spin-based logic.
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