I'm not a physicist, but isn't this kind of like building a fridge and saying it's reversing time because it makes it look like the usual process of heat dissipation is running in reverse? Or is there something more fundamental going on here?
They didn't test for eg. 010 back and forth. There might be a 000 bias, etc.
An ideal 386 computer could be thought off as not requiring energy too, right? A looping pseudo random number generator would then be time reversal. It's not saying anything really.
[0] - https://arxiv.org/abs/1405.1548
EDIT: See page 79 of the referenced paper for the detailed argument.
I believe you meant "quantum computing hasn't provided anything substantial yet". I first read it as "quantum theory hasn't provided anything substantial yet", and I was a bit shocked!
I mean, non casual filter (time travel filters!) are nothing more fancy than a post measurement analysis where we know y_n+1 at y_n, for example.
The "time reversal operator" and "time reversal symmetry" are usual technical terms in Quantum Physics, the authors didn't invent them. In an advanced quantum physics course you get 2 or 3 weeks about them, and the profesor will spend a long time explaining what they mean exactly.
The problem is that the name is too catchy and it generate a lot of misunderstanding when they are used in the press coverage of the technical articles.