Many dream of a future when we will have quantum computers, which exploit quantum mechanics to perform calculations that a modern computer simply cannot within a reasonable amount of time. Creating a quantum computer is exceedingly difficult though, in part because we do not fully know and understand what it takes to build one. Researchers at the University of Waterloo have recently proven that one property will be necessary to achieve so-called magic states, which are resistant to noise.
Quantum mechanics has been puzzling and potent properties, such as the ability for a particle to exist in two mutually exclusive states at the same time. Such particles are very fragile though and noise will cause them to collapse down to a single state, causing information to be lost. One way to protect against noise is to use magic states, which are resilient to noise. Creating and maintain magic states is very difficult though, but the Waterloo researchers have found that contextuality, a quantum property, is necessary for creating them. This property describes how the results of measuring a quantum system do not depend on what the system was prior to the measurement, but are dependent on the entire system being studied.
By showing that magic states depend on contextuality, researchers have a better understanding of the states and what the minimum requirements are for creating them. Unknown minimum requirements is a general problem for creating quantum computers as it is.
Source: University of Waterloo