Lithium-air batteries are poised to become the next revolutionary replacement for currently used lithium-ion batteries that power electric vehicles, cell phones and computers.
Category: computing – Page 817
Your Brain Isn’t a Computer — It’s a Quantum Field
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.
Enter quantum cognition : A team of researchers has determined that 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. In quantum physics, examining a particle’s state changes the state of the particle — so too, the “observation effect” influences how we think about the idea we are considering.
Quantum scientists demonstrate world-first 3D atomic-scale quantum chip architecture
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”).
A fast quantum interface between different spin qubit encodings
“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 Communications
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.