Lifeboat Foundation

UK engineers complete the build of a novel software-defined telecoms satellite called Quantum.

While our choices and beliefs don’t often make sense or fit a pattern on a macro level, at a “quantum” level, they can be predicted with surprising accuracy.

The irrationality of how we think has long plagued psychology. When someone asks us how we are, we usually respond with “fine” or “good.” But if someone followed up about a specific event — “How did you feel about the big meeting with your boss today?” — suddenly, we refine our “good” or “fine” responses on a spectrum from awful to excellent.

In less than a few sentences, we can contradict ourselves: We’re “good” but feel awful about how the meeting went. How then could we be “good” overall? Bias, experience, knowledge, and context all consciously and unconsciously form a confluence that drives every decision we make and emotion we express. Human behavior is not easy to anticipate, and probability theory often fails in its predictions of it.

Continue reading “Your Brain Isn’t a Computer — It’s a Quantum Field” »

A beautiful piece of engineering, not a quantum leap.

Powerful new system could eventually leave today’s machines in the dust.

University of New South Wales researchers at the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) have shown for the first time that they can build atomic precision qubits in a 3D device — another major step towards a universal quantum computer.

The team of researchers, led by 2018 Australian of the Year and Director of CQC2T Professor Michelle Simmons, have demonstrated that they can extend their atomic qubit fabrication technique to multiple layers of a silicon crystal — achieving a critical component of the 3D chip architecture that they introduced to the world in 2015. This new research was published today in Nature Nanotechnology (“Spin read-out in atomic qubits in an all-epitaxial three-dimensional transistor”).

The 3D architecture is touted as a major step in the development of a blueprint to build a large-scale quantum computer.

“Open Article” smile Spin-based quantum computers have the potential to tackle difficult mathematical problems that cannot be solved using ordinary computers, but many problems remain in making these machines scalable. Now, an international group of researchers led by the RIKEN Center for Emergent Matter Science have crafted a new architecture for quantum computing. By constructing a hybrid device made from two different types of qubit—the fundamental computing element of quantum computers –they have created a device that can be quickly initialized and read out, and that simultaneously maintains high control fidelity.

Single-spin qubits in semiconductor quantum dots hold promise for universal quantum computation with demonstrations of a high single-qubit gate fidelity above 99.9% and two-qubit gates in conjunction with a long coherence time. However, initialization and readout of a qubit is orders of magnitude slower than control, which is detrimental for implementing measurement-based protocols such as error-correcting codes. In contrast, a singlet-triplet qubit, encoded in a two-spin subspace, has the virtue of fast readout with high fidelity. Here, we present a hybrid system which benefits from the different advantages of these two distinct spin-qubit implementations. A quantum interface between the two codes is realized by electrically tunable inter-qubit exchange coupling. We demonstrate a controlled-phase gate that acts within 5.5 ns, much faster than the measured dephasing time of 211 ns. The presented hybrid architecture will be useful to settle remaining key problems with building scalable spin-based quantum computers.

Qubits or quantum bits are the fundamental building block for quantum information processes. Whereas conventional computers store and process data as a series of ‘1’s and ‘0’s, quantum computers use the properties of a quantum system, such as the polarization of a photon or the spin of an electron.

Read the latest Research articles in Qubits from Nature Communications.

Hacker attacks on everything from social media accounts to government files could be largely prevented by the advent of quantum communication, which would use particles of light called “photons” to secure information rather than a crackable code.

Using light to send information is a game of probability: Transmitting one bit of information can take multiple attempts. The more photons a light source can generate per second, the faster the rate of successful information transmission.

“A source might generate a lot of photons per second, but only a few of them may actually be used to transmit information, which strongly limits the speed of quantum communication,” Bogdanov said.

Continue reading “Toward unhackable communication: Single particles of light could bring the ‘quantum internet’” »