Prof. Edward H Farhi

Cecil and Ida Green Career Development Professor of Physics, Emeritus

Areas of Interest and Expertise

Elementary Particle Physics
Cosmology and General Relativity
Quantum Computation
Theoretical Particle Astrophysics
Theoretical Particle Physics
Particle Theory
Quantum Computing

Research Summary

Edward Farhi was trained as a theoretical particle physicist but has also worked on astrophysics, general relativity, and the foundations of quantum mechanics. His present interest is the theory of quantum computation.

As a graduate student, Farhi invented the jet variable "Thrust," which is used to describe how particles in high energy accelerator collisions come out in collimated streams. He then worked with Leonard Susskind on grand unified theories with electro-weak dynamical symmetry breaking. He and Larry Abbott proposed an (almost viable) model in which quarks, leptons, and massive gauge bosons are composite. With Robert Jaffe, he worked out many of the properties of a possibly stable super dense form of matter called "Strange Matter" and with Charles Alcock and Angela Olinto he studied the properties of "Strange Stars." His interest then shifted to general relativity and he and Alan Guth studied the classical and quantum prospects of making a new inflationary universe in the laboratory today. He, Guth and others also studied obstacles to constructing a time machine.

More recently, Farhi has been studying how to use quantum mechanics to gain algorithmic speedup in solving problems that are difficult for conventional computers. He and Sam Gutmann proposed the idea of designing algorithms based on quantum walks, which has been used to demonstrate the power of quantum computation over classical. They, along with Jeffrey Goldstone and Michael Sipser, introduced the idea of quantum computation by adiabatic evolution, which has generated much interest in the quantum computing community. This group was tied for first in showing that there is a problem that cannot be sped up by a quantum computer. In 2007, Farhi, Goldstone and Gutmann showed that a quantum computer can determine who wins a game faster than a classical computer. In 2010, he along with Peter Shor and others at MIT introduced a scheme for Quantum Money which so far has resisted attack.

Farhi continues to work on quantum computing but keeps a close eye on particle physics and recent developments in cosmology.

Recent Work