No journal is perfect, and despite Nature being considered a high quality journal, I have recently come across a paper which is, to put it bluntly, is slop. It is a bit of slop easily debunkable by anyone who can do a tiny bit of linear algebra.
The paper is titled “Quantum theory based on real numbers can be experimentally falsified.” The entire paper is misleading because it presents a very specific representation of quantum mechanics based solely on real numbers, shows that it leads to different predictions than traditional quantum theory, and then concludes therefore complex numbers are a necessity for complex theory.
This is obviously false. A complex number is just two real numbers stitched together. Classical computers can’t operate on complex numbers and so they just break them apart into two real floating point numbers and do the equivalent calculations in that form, but then display it as a complex number, and they can reproduce anything you can reproduce using complex numbers. Indeed, my quantum computer simulator I had put together myself uses its own complex matrix library for linear algebra, and each element of the matrix is specified by two real numbers.