  In [24], we proposed H(curl^2)-conforming elements on both a triangle and a
rectangle. This family of elements provides a brand new method to solve the
quad-curl problem in 2 dimensions. In this paper, we turn our focus to 3
dimensions and construct an H(curl^2)-conforming tetrahedral finite element.
The newly proposed element has been proved to have the optimal interpolation
error estimate. Having tetrahedral elements, we can solve the quad-curl problem
in any Lipschitz domain by conforming finite element method. We also provide
several numerical examples of using our element to solve the quad-curl problem.
The results of the numerical experiments show the effectiveness and correctness
of our element.
