As part of the International Year of Quantum celebrations, Physics Today features notable entries including this June 1999 article by John Preskill Battling Decoherence: The Fault-Tolerant Quantum Computer Quantum computers have the potential to do certain calculations faster than any foreseeable classical computers, but their success will depend on preserving complex coherent quantum states. Recent discoveries have shown us how to do that.
Figure 1: Door number 1 or door number 2? To read quantum information reliably, we need to know how it was stored.
A particularly daunting difficulty is that quantum computers are highly susceptible to making errors. The magical power of the quantum computer comes from its ability to process coherent quantum states; but such states are very easily damaged by uncontrolled interactions with the environment—a process called decoherence. In response to the challenge posed by decoherence, the new discipline of quantum error correction has arisen at the interface of physics and computer science. We have learned that quantum states can be cleverly encoded so that the debilitating effects of decoherence, if not too severe, can be resisted.
To celebrate the International Year of Quantum Science and Technology, Physics Today has assembled a collection of their coverage of quantum mechanics through the years. Visit the Quantum Archive to review the selected publications.
For a fully nostalgic experience, read this scan of the article posted by the Monroe group at Duke.
