Least energy sign-changing solutions for fractional critical Kirchhoff–Schrödinger–Poisson with steep potential well

In this paper, we consider the following Kirchhoff-Schrödinger-Poisson equation: $$\begin{aligned} \begin{aligned} \left\{ \begin{array}{lc} \left( a+b[u]_s^2\right) (-\varDelta )^s u+V_\lambda (x) u+\phi u=|u|^{p-2}u+|u|^{2_s^*-2} u &{}{} \text { in } {\mathbb {R}}^3, \\ (-\varDelta )^t \phi =u^2 &{}{} \text { in } {\mathbb {R}}^3, \end{array}\right. \end{aligned} \end{aligned}$$ where $$s \in \left( \frac{3}{4}, 1\right) , t \in (0,1),$$ $$p>4,$$ $$V_\lambda (x)=\lambda V(x)+1$$ with $$\lambda >0$$ and $$\begin{aligned} \begin{aligned}{}[u]_s^2=\int _{{\mathbb {R}}^3} \int _{{\mathbb {R}}^3} \frac{|u(x)-u(y)|^2}{|x-y|^{3+2 s}} \text {d} x \text {d} y. \end{aligned} \end{aligned}$$ Under some conditions on V, when $$\lambda >0$$ large enough and $$b>0$$ small enough, we use the deformation lemma and constrained minimization arguments to prove the existence of least energy sign-changing solutions. Additionally, we prove the least energy sign-changing solutions is strictly larger than twice that the ground state energy. In particular, a further analysis of the phenomenon of concentration for least energy sign-changing solutions as $$\lambda \rightarrow \infty $$ and $$b \rightarrow 0$$ .