Environmental Pollution

Most proposals for building a quantum computer use components that are extremely sensitive to their environment. A cosmic particle or air molecule colliding with the "quantum chip" could easily cause a catastrophic error in a quantum calculation. Similar problems can be caused by impurities or vibrations in the material used to build the chip, or in the contacts. Computers with very few qbits (up to about 5) can be shielded well enough to perform short computations, but for larger systems, shutting the environment out rapidly grows more and more difficult.

A Global Approach

Our way to overcome this problem starts by noticing that all the interactions between the system and the environment are local in nature. If we can store the information in the global, or topological properties of the states of the system, this will reduce the computer's sensitivity to its environment and bring the error rate down dramatically