 Zhu collaborated with Cao Huaidong of Lehigh University in verifying Grigori Perelman's proof of the Poincaré conjecture.The Cao–Zhu team is one of three teams formed for this purpose.The other teams were the Tian–Morgan team (Gang Tian of Princeton University and John Morgan of Columbia University) and the Kleiner–Lott team (Bruce Kleiner of Yale University and John Lott of University of Michigan).