I saw that qiskit was just incorporated in a trapped ion device.
I transpiled my circuit to 2 backends: ibm superconducting device and aqt trapped ion device. I noticed that for ibm, the $X$ gate is transpiled into $U_3(\pi,0,\pi)$, whereas for aqt it is $R_x(-\pi)$.
Since both objectives of them are to take $0$ to $1$, why do they use a different quantum gate to do that?
By the way, for the aqt device, $H$ gate $= R_y(\pi/2)R_x(\pi)$. I was wondering, why are the two representations equal?