https://www.amazon.com/Thinking-Physics-Understandable-Pract... is not free, but also excellent and gentler.
It's about gravity, not quantum field theory, but it's still very sound, very intuitive and explains the principles of the LIGO gravity wave detector. Also contains a bit of speculation about the culture and psychology of scientific creativity which I thought was great.
If you find a similar book on quantum phenomena, please post it!
You should submit this to the main page.
Of course I'm not interested in doing calculations but to appreciate quantum physics you have to know what the formalism behind are about and physicists are unable to explain it in simple terms for reasons I think I make out but can't properly formulate.
As an alternative path, Quantum Models of Cognition and Decision [1], may offer a less steep learning curve for the fact "you are the quantum system" and as such get to have actual experience with phenomena discussed in this book. To clear up the new-age vibe introduced in the last sentence, I think studying the maths through a phenomenon whose ambiguity is not questioned as a metaphysical abyss but is accepted as just being here in its mundane simplicity (semantic ambiguity in daily language use, that kind of thing) alleviates a lot of trouble in grasping what the maths mean in a physics course. Also the book is written for people coming from the fields related to psychology so it's a lot more approachable.
[1] http://bacon.umcs.lublin.pl/~lukasik/wp-content/uploads/2010...
In any event check out "The Mathematics of Quantum Mechanics" by Martin Laforest [1]. Free PDF online, totally readable and easy to follow with typical High School math background.
[1] https://uwaterloo.ca/institute-for-quantum-computing/sites/c...
I'm sure other books like Stephen Hawking's "A Brief history of Time" would be a good starting place too, but I can't speak to that one personally yet.
I spent a couple months going through its backdated articles and it was a great read