Detection of spin-flip relaxation using quantum point contacts

We measure the influence of spin-flip relaxation on the inter-landau level scattering in a quantum Hall conductor. The scattering rate increases sharp ly when hot electrons injected into the spin-down Landau level are able to spin flip and relax into the spin-up Landau level. Spin-flip relaxation pro vides energy for inelastic scattering at the sample edge. This is important for understanding the anomalous bias dependence observed between spin-reso lved longitudinal resistance peaks.