How to make smooth slow motion?

[avpromedia]

I hear there are AI that can slow down your video by guessing and generating new in-between frames.

Can AE or any adobe software do this?

I don't mean adobe express which just duplicates frames and produces a jerky slow motion.

[David Arbor]

You can use Time Remapping or a speed change on a clip in After Effects and Pixel Motion blending from Layer > Frame Blending > Pixel Motion https://helpx.adobe.com/after-effects/using/time-stretching-time-remapping.html

You can also change the speed of a clip in Premiere by choosing Optical Flow as the Time Interpolation method. https://helpx.adobe.com/premiere-pro/using/duration-speed.html 

Both options do a good job, within reason, but are slower to render than the other available options. I use Optical Flow frequently when slowing clips down in Premiere with great success. Note, you'll probably get a red render bar when you enable this option, so it's best to render your clip then play back to see how well Optical Flow worked.