Distinguishing Qubits Nanometers Apart
In a room full of people with the same name, how do you make sure the one you ask for responds? While this situation may seem somewhat silly, it is similar to an issue that has been plaguing some quantum computing research. Thankfully researchers at the University of New South Wales have devised a fairly clever way to solve the problem.
The heart of quantum computing is the quantum bits, or qubits, which have the ability to store multiple pieces of information at the same time, via superposition. Ideally for mass production, the qubits will be contained in a silicon chip, but the optimal design of such chips places them just tens of nanometers apart. That is close enough that rewriting one qubit could flip adjacent qubits as well, destroying their data. What the researchers discovered is a way to select qubits based on the number of atoms they are bonded to. The typical design of these silicon-encased qubits has them as specific, single electrons in a phosphorus atom. Changing the number of phosphorus atoms the electrons belong to though changes how they react to electromagnetic fields.
This is certainly a clever solution to a complex problem and could potentially unlock practical quantum computing on a large scale. Such computers will be able to solve problems in moments that modern electronic computers would take centuries, or longer, to complete.
Source: University of New South Wales