Quantum Computing with Very Noisy Devices

Published

March 3, 2005

Author(s)

Emanuel H. Knill

Abstract

There are quantum algorithms that can efficiently simulate quantum physics, factor large numbers and estimate integrals. As a result, quantum computers can solve otherwise intractable computational problems. One of the main problems of experimental quantum computing is to preserve fragile quantum states in the presence of errors. It is known that if the needed elementary operations (gates) can be implemented with error probabilities below a threshold, then it is possible to efficiently quantum compute arbitrarily accurately. Here we give evidence that for independent errors, the theoretical threshold is well above 3 percent, a significant improvement over earlier calculations. However, the resources required at such high error probabilities are excessive. Fortunately, they decrease rapidly with decreasing error probabilities. If we had quantum resources comparable to the considerable resources available in today's digital computers, we could implement non-trivial quantum algorithms at error probabilities as high as 1 percent per gate.

Citation

Nature

Volume

434

Pub Type

Journals

Keywords

fault-tolerance thresholds, fault-tolerant quantum computing, postselected quantum computing, quantum computing, quantum error-correcting codes, scalable quantum computing.

Citation

Knill, E. (2005), Quantum Computing with Very Noisy Devices, Nature (Accessed April 30, 2026)

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