Dynamic Kerr effect and the spectral weight transfer of the manganites

Pump-probe Kerr spectroscopy uncovers surface magnetic dynamics in Pr0.67Ca0.33MnO3 that are undetected by established methods based on optical spectral weight transfer. The connection between spin and charge dynamics in the colossally magnetoresistive manganites may thus be weaker than previously thought. Important differences from conventional ferromagnetic metals manifest as long-lived, magneto-optical coupling transients, which may be generic to all manganites.