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arXiv · 1809.06929

Spectral Evidence for Emergent Order in Ba$_{1-x}$Na$_x$Fe$_2$As$_2$

M. Yi·A. Frano·D. H. Lu·Y. He·M. Wang·B. A. Frandsen·A. F. Kemper·R. Yu·Q. Si·L. Wang·M. He·F. Hardy·P. Schweiss·P. Adelmann·T. Wolf·M. Hashimoto·S. -K. Mo·Z. Hussain·M. Le Tacon·A. E. Bohmer·D. -H. Lee·Z. -X. Shen·C. Meingast·R. J. Birgeneau
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Abstract

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba$_{1-x}$Na$_x$Fe$_2$As$_2$. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C$_4$ phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C$_4$ symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

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M. Yi, A. Frano, D. H. Lu, Y. He, M. Wang, B. A. Frandsen, A. F. Kemper, R. Yu, Q. Si, L. Wang, M. He, F. Hardy, P. Schweiss, P. Adelmann, T. Wolf, M. Hashimoto, S. -K. Mo, Z. Hussain, M. Le Tacon, A. E. Bohmer, D. -H. Lee, Z. -X. Shen, C. Meingast, R. J. Birgeneau. 2018-09-18. Spectral Evidence for Emergent Order in Ba$_{1-x}$Na$_x$Fe$_2$As$_2$. https://doi.org/10.1103/physrevlett.121.127001

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