Record Breaking Qubit CreatedCategory: Science & Technology
Posted: November 18, 2013 07:37AM
We are all fairly familiar with binary systems, such as power switches going between on and off, and data being stored as zeroes and ones. In some systems though, where quantum mechanics is the dominant form of physics, multiple mutually exclusive traits can coexist, and this is called a superposition. Superpositions, like many quantum states, are fragile though, which makes constructing a quantum computer difficult, but researchers at the University of Oxford have recently developed a qubit that survived for 39 minutes at room temperature.
The well-known Schrodinger's Cat thought experiment was originally developed to demonstrate how fragile a state can be, by showing that measuring a system can affect it. This is very true with quantum states where even a little bit of energy can cause them to collapse into classical states. Such fragility makes it very difficult to create a quantum computer that operates at temperatures much warmer than absolute zero, but the Oxford researchers were able to create a qubit at 4 K (four degrees above absolute zero) and then raise its temperature to room temperature. At 298 K (room temperature), the qubit remained in its superposition for 39 minutes, which shatters the previous record of roughly two seconds.
Such a robust qubit could greatly impact efforts to build quantum computers as it seems to have no noise. Of course there is a catch though. The qubits the researchers made consisted of phosphorus atoms doped into silicon with other elements, and all ten billion phosphorus atoms were given the same quantum state. A quantum computer will need more diversity of quantum states to be very useful.
Source: University of Oxford