Nanoscale inhomogeneity of charge density waves dynamics in La$_{2-x}$Sr$_x$NiO$_4$

Gaetano Campi; Antonio Bianconi; Boby Joseph; Shrawan Kr Mishra; Leonard Muller; Alexey Zozulya; Agustinus Agung Nugroho; Sujoy Roy; Michael Sprung; Alessandro Ricci

doi:10.1038/s41598-022-18925-y

arXiv · 2205.01518

Nanoscale inhomogeneity of charge density waves dynamics in La$_{2-x}$Sr$_x$NiO$_4$

Gaetano Campi·Antonio Bianconi·Boby Joseph·Shrawan Kr Mishra·Leonard Muller·Alexey Zozulya·Agustinus Agung Nugroho·Sujoy Roy·Michael Sprung·Alessandro Ricci

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Abstract

While stripe phases with broken rotational symmetry of charge density appear in many complex correlated systems, the heterogeneity of spatial ordering and dynamics remains elusive. This missing info is at the heart of understanding the structure and function relation in quantum complex materials. We focus here on the spatial heterogeneity of the motion of charge density wave (CDW) at nanoscale in the archetypal case of La$_{2-x}$Sr$_x$NiO$_{4+y}$ perovskite at low temperature. We report compelling evidence that the unconventional increasing motion of CDW at T < 50K is related with the decreasing of its correlation length using resonant soft X-ray photon correlation spectroscopy (XPCS). The key result of this work is the direct visualization of nanoscale spatial inhomogeneity of CDW relaxation dynamics by scanning micro X-ray diffraction (SmXRD) showing a nanoscale landscape of percolating short range dynamic CDW puddles competing with large quasi-static CDW puddles giving rise to a novel form of nanoscale phase separation of the incommensurate stripes order landscape.

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Gaetano Campi, Antonio Bianconi, Boby Joseph, Shrawan Kr Mishra, Leonard Muller, Alexey Zozulya, Agustinus Agung Nugroho, Sujoy Roy, Michael Sprung, Alessandro Ricci. 2022-03-26. Nanoscale inhomogeneity of charge density waves dynamics in La$_{2-x}$Sr$_x$NiO$_4$. https://doi.org/10.1038/s41598-022-18925-y

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