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Daniel Gottesman

Perimeter Institute

What is the Overhead Required for Fault Tolerance?

November 19, 2008 - 3:55 - 4:20pm

RLE Conference Center 36-428


The threshold theorem for fault-tolerance tells us that it is possible to build arbitrarily large reliable quantum computers provided the error rate per physical gate or time step is below some threshold value. Most research on the threshold theorem so far has gone into optimizing the tolerable error rate under various assumptions, with other considerations being secondary. However, it is certainly also desireable to minimize the overhead, both in time and number of qubits, needed to perform a large quantum computation. I will discuss what we can currently say about the overhead needed, and suggest that it might be possible, under certain circumstances, to manage with very little overhead. Whether we can do so depends on the open question of the existence of a certain class of quantum error-correcting codes with special properties.


Daniel Gottesman is a faculty member at the Perimeter Institute in Waterloo, Ontario.He received his Ph.D. at Caltech in 1997, and did postdocs at Los Alamos National Lab and Microsoft Research, after which he served in the UC Berkeley Computer Science Department as a Long-Term CMI Prize Fellow with the Clay Mathematics

He currently works on quantum computation, particularly quantum error correction, fault-tolerant quantum computation, and quantum cryptography. He is best known for developing the stabilizer code formalism for creating and describing a large class of quantum codes, and for work on performing quantum gates using quantum teleportation.

He was named to the MIT Technology Review's TR100: Top Young Innovators for 2003, and is a CIFAR Fellow in the Quantum Information Processing Program.