Electronic nematicity, the breaking of the crystal lattice rotational symmetry by the electronic fluid, is a fascinating quantum state of matter. In this work, using electronic transport under strain we investigate the electronic nematicity of BaNi₂(As_1−xP_x)₂, a candidate system for charge-induced nematicity. We report a large B_1g elastoresistance coefficient that is maximized at the tetragonal-to-orthorhombic transition temperature, that slightly precedes the first-order triclinic transition. An hysteretic behavior is observed in the resistance versus strain sweeps and interpreted as the pinning of orthorhombic domains. Remarkably, the elastoresistance only onsets together with a strong enhancement of the incommensurate charge density wave of the material, strongly suggesting that this electronic instability is uniaxial in nature and drive the orthorhombic transition. The absence of sizeable elastoresistance above this electronic phase clearly contrasts dynamic and static electronic nematicity. Finally, the elastoresistance temperature dependence that strongly differs from the Curie-Weiss form of iron-based superconductors reveals major differences for the respective coupling of electronic nematicity to the lattice. Our results uncover an extremely strain-sensitive platform to study electronic anisotropy induced by a charge-density-wave instability.

电子向列性，电子流体破坏晶格旋转对称性，是一种迷人的物质量子态。_{在这项工作中，我们使用应变下的电子传输研究了 BaNi 2} (As _{1− x} P _x ) ₂的电子向列性，这是电荷诱导向列性的候选系统。我们报大B _1g弹性电阻系数在四方晶系到正交晶系转变温度下达到最大值，该温度略早于一级三斜晶系转变。在电阻与应变扫描中观察到滞后行为，并将其解释为正交晶域的钉扎。值得注意的是，弹性电阻仅与材料的不相称电荷密度波的强烈增强一起出现，强烈表明这种电子不稳定性本质上是单轴的并驱动正交相变。在这个电子相之上没有相当大的弹性电阻明显对比动态和静态电子向列性。最后，与居里-魏斯形式的铁基超导体截然不同的弹性电阻温度依赖性揭示了电子向列性与晶格各自耦合的主要差异。我们的结果揭示了一个对应变极其敏感的平台，用于研究由电荷密度波不稳定性引起的电子各向异性。