Abstract
We present an infrared spectroscopy study of the magnetic topological insulator MnBi4Te7 with antiferromagnetic(AFM)order below the Néel temperature TN=13 K.Our investigation reveals that the low-frequency optical conductivity consists of two Drude peaks,indicating a response of free carriers involving multiple bands.Interestingly,the narrow Drude peak grows strongly as the temperature decreases,while the broad Drude peak remains relatively unchanged.The onset of interband transitions starts around 2000 cm-1,followed by two prominent absorption peaks around 10000 cm-1 and 20000 cm-1.Upon cooling,there is a notable transfer of spectral weight from the interband transitions to the Drude response.Below TN,the AFM transition gives rise to small anomalies of the charge response due to a band reconstruction.These findings provide valuable insights into the interplay between magnetism and the electronic properties in MnBi4Te7.
基金项目
the National Natural Science Foundation of China(12274442)
National Key R&D Program of China(2022YFA1403901)
万方数据