I dislike "which is better" questions, because usually, "better" depends very much on the environment.
Qt is not new technology. I have a circa 2006 Sharp Zaurus SL6000 that relies extensively on Qt for its GUI. However, unless Nokia or somebody recently provided one, I don't know of a
Java API for it. It was traditionally programmed in C.
Both Qt and JME are designed to run well on mobile devices. JME/J2ME is probably available on a wider variety of devices, but if you're thinking Qt on Symbian, the total number of devices running it might (at the moment) be higher than for JME.