Measurement of coherent polarons in the strongly coupled antiferromagnetically ordered iron-chalcogenide Fe1.02Te using angle-resolved photoemission spectroscopy.

Journal article

The nature of metallicity and the level of electronic correlations in the antiferromagnetically ordered parent compounds are two important open issues for the iron-based superconductivity. We perform a temperature-dependent angle-resolved photoemission spectroscopy study of Fe(1.02)Te, the parent compound for iron chalcogenide superconductors. Deep in the antiferromagnetic state, the spectra exhibit a "peak-dip-hump" line shape associated with two clearly separate branches of dispersion, characteristics of polarons seen in manganites and lightly doped cuprates. As temperature increases towards the Néel temperature (T(N)), we observe a decreasing renormalization of the peak dispersion and a counterintuitive sharpening of the hump linewidth, suggestive of an intimate connection between the weakening electron-phonon (e-ph) coupling and antiferromagnetism. Our finding points to the highly correlated nature of the Fe(1.02)Te ground state featured by strong interactions among the charge, spin, and lattice and a good metallicity plausibly contributed by the coherent polaron motion.

Authors: Liu, Z; He, R; Lu, D; Yi, M; Chen, Y

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 110
• Issue: 3
• Pages: 037003
• Publication date: 2013-01-01
• DOI: 10.1103/physrevlett.110.037003
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English