After spending more than one year as a postdoc with Michael Tinkham in Berkeley, he returned in 1965 to Germany where he obtained a chair for theoretical physics in 1968 at the Johann Wolfgang Goethe University in Frankfurt/M.
After his retirement in 2007 he became president of the Asia Pacific Center for Theoretical Physics and a faculty member at POSTECH in Pohang (Korea).
Fulde has made numerous contributions to condensed matter physics including superconductivity and correlated electrons in molecules and solids.
Fulde was a founding member of the Berlin-Brandenburg Academy of Sciences and Humanities (former Preussische Akadamie der Wissenschaften).
He was a member of the German Academy of Sciences Leopoldina and Deutsche Akademie für Technikwissenschaften (acatech).