PIRSA:12050041  ( MP4 Medium Res , MP4 Low Res , MP3 , PDF ) Which Format?
Far Infrared Study of Magnetic Field Induced Normal States of La1.94Sr0.06CuO4
Speaker(s): Tom Timusk
Abstract: We report on the ab-plane optical properties of the magnetic field inducednormal state of underdoped La1.94Sr0.06CuO(Tc=5.5 K), the first such study. We apply strong magnetic fields (4 T and 16 T) along the c-axis. We find that a 4 T field is strong enough to destroy the superconducting condensate.  However at higher fields we observed a gap-like depression in the optical conductivity at low frequency along with parallel growth of a broad absorption peak at higher frequency just above the 5 meV gap. The loss of low frequency conductivity in the gap region is in good agreement with dc magneto resistance measurements on samples from the same batch.  The spectral weight loss in the depression at low frequency is recovered by the spectral weight in the broad peak. Significantly, this spectral weight equals the spectral weight of the superconducting condensate.  The broad peak tracks the SDW order seen by neutron scattering[1] and we suggest offers an optical signature of magnetism.
Date: 03/05/2012 - 4:30 pm
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