I have been playing around with the qecsim Python library and a question has come to my thoght. Whenever I try to represent the logical error rate dependence with the physical error rate for several planar code distances the even ones do not intersect with the probability threshold, but the rest always do. Then I saw that most of the articles consider odd distances. Why is that?
My first thought has been to be the existence of a given symmetry for even distance codes which make their error detection to be worse, but I am not sure. I have been looking for the answer in articles online but could not find it. Does anyone know why?
Thank you very much in advance!