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Error Rate Reduced for Scalable Quantum Technology

A scalable system for controlling quantum bits demonstrates a very low error rate, which is essential for making practical devices.

A major obstacle to the development of practical quantum computers is the difficulty of scaling up—making a device with large numbers of quantum bits (qubits) that also gives accurate results in the presence of environmental noise. Now researchers report a significant improvement in the accuracy of a technology that is already known to be much easier to scale up than conventional techniques [1]. This alternative technology uses units of magnetic flux called flux quanta to control conventional superconducting qubits. The reduction in the error rate came from physically separating the control circuits from the qubits. With further refinement, the flux-quanta technology could provide a superior pathway to practical quantum computation.

Many current efforts to carry out quantum logic operations—the basic units of computation—use short microwave pulses to control the qubits. Currently, however, this technology is difficult to scale up beyond 1,000 qubits. But the presence of environmental noise requires error-correction methods that rely on large numbers of qubits, perhaps a million or more, for an effective error-correcting system that performs useful computations, according to some estimates.

Researchers observe strongest quantum contextuality in single system

A team led by Prof. Li Chuanfeng and Prof. Xu Jinshi from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), collaborating with Prof. Chen Jingling from Nankai University and Prof. Adán Cabello from the University of Seville, studied the single-system version of multipartite Bell nonlocality, and observed the highest degree of quantum contextuality in single system. Their work was published in Physical Review Letters.

Quantum contextuality refers to the phenomenon that the measurements of quantum observables cannot be simply considered as revealing preexisting properties. It is a distinctive feature in and a crucial resource for quantum computation. Contextuality defies noncontextuality hidden-variable theories and is closely linked to .

In multipartite systems, quantum arises as the result of the contradiction between quantum contextuality and noncontextuality hidden-variable theories. The extent of nonlocality can be measured by the violation of Bell and previous researches showed that the violation increases exponentially with the number of quantum bits involved. However, while single-particle high-dimensional system offers more possibilities for measurements compared to multipartite systems, the quest to enhance contextual correlation’s robustness remains an ongoing challenge.

Understanding consciousness within the known laws of physics (Carlo Rovelli)

Abstract: I do not share the feeling that consciousness (whatever this means) cannot be understood in the context of the known physical laws. So far we do not understand it well, but neither do we fully understand thunderstorms, for that matter. I offer three small contributions in the direction of a direct naturalistic account of consciousness: (i) a purely physical account of agency and the openness of the future, which traces the source of information to past low entropy; (ii) a purely physical basis for a simple notion of “meaning”; and (iii) a suggestion that current understanding of quantum matter (without need of panpsychism) weakens the apparent hiatus between the mental and the physical.

Shrinking light: Waveguiding scheme enables highly confined subnanometer optical fields

Imagine shrinking light down to the size of a tiny water molecule, unlocking a world of quantum possibilities. This has been a long-held dream in the realms of light science and technology. Recent advancements have brought us closer to achieving this incredible feat, as researchers from Zhejiang University have made groundbreaking progress in confining light to subnanometer scales.

Traditionally, there have been two approaches to localize light beyond its typical diffraction limit: dielectric confinement and plasmonic confinement. However, challenges such as precision fabrication and optical loss have hindered the confinement of optical fields to sub-10 nanometer (nm) or even 1-nm levels. But now, a new waveguiding scheme reported in Advanced Photonics promises to unlock the potential of subnanometer optical fields.

Picture this: Light travels from a regular , embarking on a transformative journey through a fiber taper, and finds its destination in a coupled-nanowire-pair (CNP). Within the CNP, the light morphs into a remarkable nano-slit mode, generating a confined optical field that can be as tiny as a mere fraction of a nanometer (approximately 0.3 nm). With an astonishing efficiency of up to 95% and a high peak-to-background ratio, this novel approach offers a whole new world of possibilities.

How Oppeheimer Visualizes “Almost Magical” Shift “From Classic Physics to Quantum Physics”

Similar to Interstellar, Oppenheimer (now in theaters) finds Christopher Nolan at his most abstract, with the director working overtime to ascribe a visual language to concepts just beyond our comprehension.

It wasn’t enough to simply make a biopic about the father of the atomic bomb — he needed to take us inside the extraordinary theoretical mind of J. Robert Oppenheimer (played in the film by Cillian Murphy) and show us the Big Bang-like birth of quantum physics and how it directly led to the creation of the atomic bomb.

RELATED: Oppenheimer’s Atomic Bombs Marked a New Geologic Age of Humans.

A quantum radar that outperforms classical radar by 20%

Quantum technologies, a wide range of devices that operate by leveraging the principles of quantum mechanics, could significantly outperform classical devices on some tasks. Physicists and engineers worldwide have thus been working hard to achieve this long-sought “quantum advantage” over classical computing approaches.

A research team at Ecole Normale Supérieure de Lyon, CNRS recently developed a quantum that could significantly outperform all existing radars based on classical approaches. This new radar, introduced in a paper published in Nature Physics, concurrently measures an entangled probe and the idler photon states occurring once this probe reflects from target objects, merging with thermal noise.

“We invented a superconducting circuit in 2020 that was able, among other things, to generate entanglement, store and manipulate microwave quantum states and count the number of photons in a microwave field,” Benjamin Huard, one of the researchers who carried out the study, told Phys.org. “We then realized that it had all the features we needed to tackle one of the biggest challenges in microwave quantum metrology: demonstrating a in radar sensing.”

Does Einstein’s Theory of Special Relativity Suggest That There Is an Afterlife?: A Theoretical Physicist Explains

“Let’s talk about the physics of dead grandmothers.” Thus does theoretical physicist Sabine Hossenfelder start off the Big Think video above, which soon gets into Einstein’s theory of special relativity. The question of how Hossenfelder manages to connect the former to the latter should raise in anyone curiosity enough to give these ten minutes a watch, but she also addresses a certain common category of misconception. It all began, she says, when a young man posed to her the following question: “A shaman told me that my grandmother is still alive because of quantum mechanics. Is this right?”

Upon reflection, Hossenfelder arrived at the conclusion that “it’s not entirely wrong.” For decades now, “quantum mechanics” has been hauled out over and over again to provide vague support to a range of beliefs all along the spectrum of plausibility. But in the dead-grandmother case, at least, it’s not the applicable area of physics. “It’s actually got something to do with Einstein’s theory of special relativity,” she says. With that particular achievement, Einstein changed the way we think about space and time, proving that “everything that you experience, everything that you see, you see as it was a tiny, little amount of time in the past. So how do you know that anything exists right now?”