Nematicity, Charge Density Waves and Lattice Distortions in BaNi2(As1-xPx)2

Most clearly observed in iron-based superconductors, nematicity is often thought as originating from magnetic fluctuations. Recently, an analogue to iron-based superconductors, BaNi2As2, has emerged as a promising candidate for a novel type of nematicity triggered by charge fluctuations [1,2,3].

In this talk, we discuss electrical transport measurements under strain, directly probing the nematic susceptibility of BaNi2(As1-xPx)2 with 0≤x≤0.10. We resolve, across the entire substitution range investigated, a well-defined response in the B1g (x2-y2) channel. Interestingly, the temperature dependence of the B1g elastoresistance in BaNi2(As1-xPx)2 markedly contrast with those of BaFe2As2 in the B2g (xy) channel, indicating important differences for the corresponding susceptibilities above the four-fold symmetry breaking phases. Finally, our measurements indicate a close, yet complex, relationship of the strain-dependent electrical resistance with both charge ordering and structural distortions.