QM really makes me confused. Classical Theories gone wrong in QM. I want to ask, why phase factor=e^(kx-wt+phi) ? The induction of Schrodinger's equation is easy. but where is this e^(kx-wt+phi) come from?

Momentum is proportional to frequency. p=hf
Can we measure motion which smaller than h-bar? and now, why is h-bar?