Infrared study of the interplay of charge, spin, and lattice excitations in the magnetic topological insulator EuIn2As2

Article

关键词: ELECTRICAL-RESISTIVITY;   

DOI  :  10.1103/PhysRevB.103.245101

来源: SCIE

【 摘 要 】

We report an infrared spectroscopy study of the axion topological insulator candidate EuIn2As2 for which the Eu moments exhibit an A-type antiferromagnetic (AFM) order below T-N similar or equal to 18 K. The low-energy response is composed of a weak Drude peak at the origin with a plasma frequency of about 2000 cm(-1) and a pronounced infrared-active phonon mode at 185 cm(-1). The interband transitions start above 800 cm(-1) and give rise to a series of weak absorption bands at 5000 and 12 000 cm(-1) and strong ones at 20 000, 27 500, and 32 000 cm(-1). The AFM transition leads to pronounced anomalies of the charge response in terms of a cusp-like maximum of the free carrier scattering rate around T-N and large magnetic splittings of the interband transitions at 5000 and 12 000 cm(-1). The phonon mode at 185 cm(-1) has also an anomalous temperature dependence around T-N which suggests that it couples to the fluctuations of the Eu spins. The combined data provide evidence for a strong interaction among the charge, spin, and lattice degrees of freedom.

【 授权许可】

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