Zero-Field Quantized Anomalous Hall Resistance of (Bi,Sb)2 Te3

In the quantum anomalous Hall effect, the edge states of a ferromagnetically doped topological insulator exhibit quantized Hall resistance and dissipationless transport at zero magnetic field. Here, we present a measurement of the resistance quantization of V-doped (Bi,Sb)2Te3 devices in zero external magnetic field. For the deviation of the quantized anomalous Hall resistance from R
_K
we determined a value of 0.17±0.25μΩ/Ω.. This is a step towards realization of a practical zero-field quantum resistance standard which in combination with the Josephson effect could provide the universal quantum units standard in the future.