Relevant paper: https://iopscience.iop.org/article/10.1088/0143-0807/8/2/006...

Abstract: "According to the weak form of the equivalence principle all objects fall at the same rate in a gravitational field. However, recent calculations in finite-temperature quantum field theory have revealed that at T>0 heavier and/or colder objects actually fall faster than their lighter and/or warmer counterparts. This unexpected result is demonstrated using elementary quantum mechanical arguments."

Downloadable here: https://www.academia.edu/download/109363694/download.pdf