> Do you know by chance if there are similar companies (complex engineering, with physics, maths, chemistry, computer science, ...) that are located in Switzerland?

I've only worked with their products and not a whole lot with the people but Sensirion [0] is very close to Zürich and is ranked one of the best employers in Switzerland while seemingly being at the intersection of the things it seems you're interested in.

Switzerland is also full of manufacturing equipment suppliers (e.g. Schaublin and GF Machining Solutions, the entire "Watch Valley") and manufacturing is full of intersections between physics/maths/chemistry/software engineering.

Plus there's the pharmaceutical companies.

For a small country, I think Switzerland is about the best place for you to be.

[0] https://www.sensirion.com/en/