near the charge order (CO) transition*

The nature of the dynamics of charge-ordered states in underdoped cuprates has been of great recent interest. Our work on La_2-xBa_xCuO₄ with x=0.125 (LBCO) in zero magnetic field (H) reveals the presence of dynamic behavior within the charge-ordered state in the form of avalanches, similar to that in La_1.48Nd_0.4Sr_0.12CuO₄ (LNSCO). In LNSCO, avalanches were also observed to be asymmetrically driven by H around the concurrent CO and structural transition with an additional onset of negative magnetoresistance (MR), which was attributed to the emergence of CO [1]. In La_1.7Eu_0.2Sr_0.12CuO₄ (LESCO) negative MR, albeit with no avalanches, was observed at the onset of CO but not at the higher temperatures around the structural transition [1]. The presence of avalanches and overlap of the CO and structural transitions in LBCO present the opportunity to clarify the role of the LNSCO Nd³⁺ moments and the origin of the negative MR. Therefore, we report the H = 0 findings and the study of H || c magnetoresistance of LBCO near the CO transition.
[1] P. G. Baity et al., Phys. Rev. Lett. 120, 156602 (2018).