Here are some key Jewish figures involved in the building of the nuclear bomb. This list is nowhere near exhaustive as it only includes some of the key contributors and none of the minor contributors:
J. Robert Oppenheimer: Director of the Los Alamos branch of the Manhattan Project
Leo Szilard: A Hungarian-born Jewish physicist, Szilard is credited with initiating the project by persuading Albert Einstein to write a letter to President Roosevelt. He also patented a nuclear reactor design with Enrico Fermi.
Edward Teller: A Hungarian-American physicist, Teller was a key figure in the development of the hydrogen bomb, a more powerful successor to the atomic bomb.
Hans Bethe: A German-born physicist, Bethe led the theoretical division at Los Alamos and made significant contributions to understanding nuclear reactions.
Eugene Wigner: A Hungarian-American physicist, Wigner played a vital role in the development of nuclear reactors and the separation of uranium isotopes.
Felix Bloch: A Swiss physicist, Bloch contributed to the theoretical understanding of nuclear physics.
Niels Bohr: A Danish physicist, Bohr provided crucial insights into nuclear fission and was instrumental in the early stages of the project.
John von Neumann: A Hungarian-American mathematician, von Neumann played a key role in the development of the bomb's detonation system.
Richard Feynman: An American theoretical physicist who worked on the development of the bomb's detonation system.
Otto Frisch: An Austrian-British physicist, Frisch was involved in early calculations about the critical mass of uranium needed for a nuclear explosion.
Rudolf Peierls: A German-British physicist, Peierls co-authored a report with Frisch that first calculated the critical mass of uranium.
These are just a few examples, and many other Jewish scientists contributed to the Manhattan Project in various capacities. If you are interested in Hungarian Jews in particular you should read up on the "Martians". Some interesting friends who grew up together and learned some math along the way. Those guys included
Leo Szilard: A physicist who conceived the nuclear chain reaction.
John von Neumann: A mathematician known for his work on game theory and the development of the modern computer.
Eugene Wigner: A physicist who won a Nobel Prize for his work on symmetries in physics.
Edward Teller: A physicist known as the "father of the hydrogen bomb".
Theodore von Kármán: A fluid dynamicist who helped establish NASA's Jet Propulsion Laboratory.
Paul Erdős: A highly prolific mathematician known for his collaborative work.