Atmos as I understand it is firing sound up in the air, there may be some soundbars that sort of do it but you need like a 7.1 setup or something I would say.
But I think they have also released some sort of Atmos thing on Apple that just works on normal headphones...
There are soundbars that play atmos without any other speakers. 7.1 speakers are other way to play it. Also some headphones can do the trick but that's the lowest way of atmos.
In other words, for a 100% experience you need the 7.1 speakers, the soundbar is pretty similar, and the headphones gives you a better sound than a stereo mix but obviously you loose the space experience of having the sound surrounding you through the room. That's what I understood from all what I read, and the experience I had with a soundbar in a music shop was like having musicians playing behind me, in front of me, at my right, left, up... quite an experience.
