1Institute of Physics, Chinese Academy of Sciences, Beijing 100190 2International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871 3Collaborative Innovation Center of Quantum Matter, Beijing 100871
Abstract：We report an optical spectroscopy study on LaSb, a compound recently identified to exhibit extremely large magnetoresistance. Our optical measurement indicates that the material has a low carrier density. More interestingly, the study reveals that the plasma frequency increases with decreasing temperature. This phenomenon suggests either an increase of the conducting carrier density or/and a decrease of the effective mass of carriers with decreasing temperature. We attribute it primarily to the latter effect. Two possible scenarios on its physical origin are examined and discussed. The study offers new insight into the electronic structure of this compound.
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2017, Vol. 34 
