Selective spin-resolved edge-current injection into a quantum antidot

Quantum-Hall edge states have an extremely long equilibration length. We have utilized this property to inject a spin-polarized tunneling current into a quantum antidot. This allows the determination of the transmission of each spin channel, which is not possible in conventional conductance measurements. It was found that only one spin contributes to the resonance in the double-frequency regime in accordance with our proposed model with compressible rings. This technique is applicable as a spin-injection method in nanodevices.