quantum computer tagged posts

By evaporating indium gallium arsenide onto a gallium arsenide substrate TUM physicists created nanometer-scale hills, so-called quantum dots. An electron trapped in one of these quantum dots can be used to store information. Hitherto unknown memory loss mechanisms could be switched off by applying a magnetic field. Credit: Fabian Flassig / TUM

Magnetic field helps qubit electrons store information longer. Physicists have tracked down semiconductor nanostructure mechanisms that can result in the loss of stored information – and halted the amnesia using an external magnetic field. The new nanostructures comprise common semiconductor materials compatible with standard manufacturing processes.

In principle, there are various possibilities of implementing qubits: photons are an option equally ...

Artist’s rendition of optically-defined quantum circuits in a topological insulator. Credit: Peter Allen

In contrast to using advanced nanofabrication facilities based on chemical processing of materials, this flexible technique allows for rewritable ‘optical fabrication’ of devices. The electrons in topological insulators have unique quantum properties useful for developing low-power spin-based electronics and quantum computers. However, making even the simplest experimental circuits with these materials has proved difficult because traditional semiconductor engineering techniques tend to destroy their fragile quantum properties. Even a brief exposure to air can reduce their quality.

The researchers report the discovery of an optical effect that allows them to “tune” the energy of electro...

This is the silicon based quantum optics lab-on-a-chip. Credit: University of Bristol

The microprocessor inside a computer is a single multipurpose chip that has revolutionized people’s life, allowing them to use one machine to surf the web, check emails and keep track of finances. Now, researchers have pulled off the same feat for light in the quantum world by developing an optical chip that can process photons in an infinite number of ways.

It’s a major step forward in creating a quantum computer to solve problems such as designing new drugs, superfast database searches, and performing otherwise intractable mathematics that aren’t possible for super computers...