I want to have a vector with a superscript:
But this gives very bad results: the t is overlapping with the vector arrow. How do I fix this (and why does this give bad results in the first place) ?
I don't really know why the result is bad; I suspect it has to do with the width of the letter. I wouldn't use such a notation, but that's a personal opinion.
the superscript is moved a bit to the right. One might perhaps let TeX do some computations in order that the shift to the right of the superscript is automatic.
(I have included egreg's code to make the comparison easier.)
The first two are done using the