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arXiv · 1608.04799

Evidence for a nematic phase in La$_{1.75}$Sr$_{0.25}$NiO$_{4}$

Ruidan Zhong·Barry L. Winn·Genda Gu·Dmitry Reznik·J. M. Tranquada
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Abstract

Determining the nature of electronic states in doped Mott insulators remains a challenging task. In the case of tetragonal La$_{2-x}$Sr$_{x}$NiO$_{4}$, the occurrence of diagonal charge and spin stripe order in the ground state is now well established. In contrast, the nature of the high-temperature "disordered" state from which the stripe order develops has long been a subject of controversy, with considerable speculation regarding a polaronic liquid. Following on the recent detection of dynamic charge stripes, we use neutron scattering measurements on an $x=0.25$ crystal to demonstrate that the dispersion of the charge stripe excitations is anisotropic. This observation provides compelling evidence for the presence of electronic nematic order.

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Ruidan Zhong, Barry L. Winn, Genda Gu, Dmitry Reznik, J. M. Tranquada. 2017-05-02. Evidence for a nematic phase in La$_{1.75}$Sr$_{0.25}$NiO$_{4}$. https://doi.org/10.1103/physrevlett.118.177601

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