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Category: quantum physics – Page 320

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.

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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.

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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.

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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.”

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“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?”

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Various reports say the claim is far from true.

Russian scientists are claiming that they have created the most powerful quantum computer in the history of their nation. They even presented the computer to Russian President Vladimir Putin, who visited the exhibition of quantum technology achievements by Rosatom, the State Nuclear Energy Corporation.

But as per a report, the claim is far from true and the computer won’t be breaking modern encryption codes anytime soon.

Rosatom.

They even presented the computer to Russian President Vladimir Putin, who visited the exhibition of quantum technology achievements by Rosatom, the State Nuclear Energy Corporation.

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We have implemented a nonlinear quadrature measurement of \(\hat{p}+\gamma {\hat{x}}^{2}\) using the nonlinear electro-optical feedforward and non-Gaussian ancillary states. The nonlinear feedforward makes the tailored measurement classically nonlinear, while the ancillary state pushes the measurement into highly non-classical regime and determines the excess noise of the measurement. By using a non-Gaussian ancilla we have observed 10% reduction of the added noise relative to the use of vacuum ancillary state, which is consistent with the amount of nonlinear squeezing in the ancilla. Higher reduction of the noise can be realized in the near future by a better approximation of the CPS using a superposition of higher photon number states38,42. We can now create broadband squeezed state of light beyond 1 THz8,9 and can make a broadband amplitude measurement on it with 5G technology beyond 40 GHz10, as well as a broadband photon-number measurement beyond 10 GHz11. Furthermore, the nonlinear feedforward presented here can be compatible with these technologies if an application specific integrated circuit (ASIC) is developed based on the FPGA board presented here. By using such technologies we can efficiently create non-Gaussian ancillary states with large nonlinear squeezing by heralding schemes36,43 even when the success rate is very low. It is because we can repeat heralding beyond 10 GHz and can compensate for the very low success rate.

When supplied with such high-quality ancillary state, this nonlinear measurement can be directly used in the implementation of the deterministic non-Gaussian operations required in the universal quantum computation. Our experiment is a key milestone for this development as it versatilely encompasses all the necessary elements for universal manipulation of the cluster states. Furthermore, this method is extendable to multiple ancillary states case in implementation of the higher-order quantum non-Gaussianity44 and multi-mode quantum non-Gaussianity45.

Our experiment demonstrates an active, flexible, and fast nonlinear feedforward technique applicable to traveling quantum states localized in time. If the nonlinear feedforward system is combined with the cluster states13,14 and GKP states19, all operations required for large-scale fault-tolerant universal quantum computation can be implemented in the same manner. As such, we have demonstrated a key technology needed for optical quantum computing, bringing it closer to reality.

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