identically equal to 1. Therefore the delocalization condition is a much weaker condition.

There are three different ways in which the nonrandomness or uniformity of $\beta/\epsilon$ can be achieved. If only the scalar potential $u$ (therefore, only $\epsilon$) is random and the vector potential is constant, then we are forced to set $\beta=0$ in order to make $\beta/\epsilon$ nonrandom. In this case, the wave is delocalized at the incident angle $\theta_R$ satisfying $$\begin{aligned}
\sin\theta_R=-a_0,
\label{eq:angle1}\end{aligned}$$ where $\vert a_0\vert<1$. When $a_0$ is zero, this gives $\theta_R=0$, which is the same as the total transmission condition and corresponds to the usual Klein tunneling of normally-incident massless Dirac electrons in a 1D random scalar potential. In general cases where $a_0$ is nonzero, however, this condition is different from Eq. (\[eq:ktc\]) and the two angles $\theta_R$ and $\theta_K$ are different. Since the medium is effectively uniform when the wave is incident at $\theta_R$, it propagates without an exponential decay. However, since the effective impedance given by $\eta=\vert\cos\theta_R\vert^{-1}$ is not equal to 1, the wave is reflected at the interfaces and the disorder-averaged transmittance of a strip of finite thickness is smaller than 1.

Secondly, when only the vector potential $a$ (therefore, only $\beta$) is 