Using exotic components such as color codes, new phases of quantum matter, and extra dimensions, a team of physicists has shown that it’s theoretically possible to construct a quantum computer that has the ability to correct itself whenever an error occurs.
“The greatest significance of our work is showing that self-correcting quantum computing at a finite temperature is not impossible as a matter of principle,” physicist Héctor Bombin told Phys.org. Bombin was at MIT in Cambridge, Massachusetts, while performing the study and is currently at the Perimeter Institute in Waterloo, Ontario. “In fact, the original motivation came from claims to the contrary by other authors. We provide explicit constructions that can be checked directly, without numerical simulations.”
Bombin and his coauthors have published a paper on their proposed self-correcting quantum computer in a recent issue of the New Journal of Physics.
Error correction in quantum computers cannot be performed the same way as inclassical computers, where information is stored multiple times for redundancy. Since copying quantum information is impossible due to the no-cloning theorem, physicists must find other ways to protect quantum information against errors.
As Bombin and his coauthors explain in their paper, quantum computers can be classified into three categories based on their protection against errors.
The first type is bare quantum computers, which do not have any type of error correction. These quantum computers have already been realized with ion traps and optical lattices.
The second type is externally protected quantum computers, which can be acted upon externally in order to repair errors. Although this type has not been successfully implemented yet, theoretical studies indicate that there are no fundamental obstacles to reach them when quantum technologies are fully developed.
Read more at: Phys.org