In the quantum realm, at least insofar as we can understand, particles are in a state of superposition, wherein they exist in two or more states simultaneously -- a cat that is both dead and alive, so to speak. However, this "coherence" lasts for only a fraction of a second before the whole system decoheres -- a phenomenon that marks the transition from the realm of quantum to classical mechanics. The fact that a coherent quantum state is short-lived is what allows reality as we know it to exist, but, for researchers looking to exploit superposition to create quantum computers, this presents a major roadblock. For these researchers, looking for ways to least delay decoherence -- thereby preserving the state of superposition that makes quantum computers so much faster than their conventional counterparts -- is a key goal. Read: Schrödinger's Cat Is Now Dead And Alive In Two Boxes Now, in a study published in the latest edition of the journal Quantum Science and Technology, a team of researchers has demonstrated the storage and retrieval of quantum information in a single atom of phosphorus embedded in a silicon crystal.
Engineers at the University of New South Wales (UNSW) have announced the invention of a "radical" architecture for quantum computing, essentially allowing quantum bits (qubits) -- the basic unit of information in a quantum computer -- to be placed hundreds of nanometres apart and still remain coupled. The invention is based on novel "flip-flop qubits" that UNSW said promises to make the large-scale manufacture of quantum chips dramatically cheaper and easier. To operate the flip-flop qubit, researchers need to pull the electron away from the nucleus, using the electrodes at the top; doing so creates an electric dipole. The conceptual breakthrough is the creation of an entirely new type of qubit using both the nucleus and the electron. The new chip design allows for a silicon quantum processor that can be scaled up without the precise placement of atoms required in other approaches.
Australia and France have announced a partnership that will see both countries work together on quantum computing. Signing a Memorandum of Understanding (MoU) on Wednesday, Australian Prime Minister Malcolm Turnbull and President of France Emmanuel Macron said the partnership is the "tangible next step" in the development of a silicon quantum computer. Under the MoU, Australia's first quantum computing company, Silicon Quantum Computing (SQC), and France's research and development (R&D) organisation, the Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), will form a joint venture in silicon CMOS quantum computing technology that will see a focus on technology development, as well as commercialisation opportunities, as they strive to develop a quantum computer. The organisations are striving towards the manufacture and industrialisation of quantum computing hardware. SQC was launched in August to take advantage of and commercialise the work done by the University of New South Wales (UNSW) in the quantum space.
The race to create superfast computers is accelerating. A rethink of one of the most fundamental parts of a quantum computer could pave the way for ultra-powerful devices. Andrea Morello at the University of New South Wales in Australia and his colleagues have a design for a qubit – the smallest unit of quantum information – that could help get round some of the difficulties of manufacturing quantum computers at an atomic scale. At the moment, making quantum systems using silicon is difficult because the qubits have to be very close to each other, about 10 to 20 nanometres apart, in order to communicate. This leaves little room to place the electronics needed to make a quantum computer work.
Sandia National Laboratories has taken a first step toward creating a practical quantum computer, able to handle huge numbers of computations instantaneously. A "donor" atom propelled by an ion beam is inserted very precisely in microseconds into an industry-standard silicon substrate. The donor atom -- in this case, antimony (Sb) --carries one more electron (five) than a silicon atom (four). Because electrons pair up, the odd Sb electron remains free. Instruments monitor the free electron to determine if, under pressure from an electromagnetic field, it faces up or down, a property called "spin."