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Archive for the ‘quantum physics’ category: Page 451

Sep 11, 2020

Study identifies limits on the efficiency of techniques for reducing noise in quantum resources

Posted by in categories: computing, quantum physics

Quantum technologies, such as quantum computers, quantum sensing devices and quantum memory, have often been found to outperform traditional electronics in speed and performance, and could thus soon help humans to tackle a variety of problems more efficiently. Despite their huge potential, most quantum systems are inherently susceptible to errors and noise, which poses a serious challenge to implementing and using them in real-world settings.

Sep 10, 2020

Quirky response to magnetism presents quantum physics mystery

Posted by in categories: particle physics, quantum physics

The search is on to discover new states of matter, and possibly new ways of encoding, manipulating, and transporting information. One goal is to harness materials’ quantum properties for communications that go beyond what’s possible with conventional electronics. Topological insulators—materials that act mostly as insulators but carry electric current across their surface—provide some tantalizing possibilities.

“Exploring the complexity of topological materials—along with other intriguing emergent phenomena such as and superconductivity—is one of the most exciting and challenging areas of focus for the materials science community at the U.S. Department of Energy’s Brookhaven National Laboratory,” said Peter Johnson, a senior physicist in the Condensed Matter Physics & Materials Science Division at Brookhaven. “We’re trying to understand these topological insulators because they have lots of potential applications, particularly in quantum information science, an important new area for the division.”

For example, materials with this split insulator/conductor personality exhibit a separation in the energy signatures of their surface electrons with opposite “spin.” This quantum property could potentially be harnessed in “spintronic” devices for encoding and transporting information. Going one step further, coupling these electrons with magnetism can lead to novel and exciting phenomena.

Sep 10, 2020

Joscha Bach — GPT-3: Is AI Deepfaking Understanding?

Posted by in categories: existential risks, information science, mathematics, media & arts, particle physics, quantum physics, robotics/AI, singularity

On GPT-3, achieving AGI, machine understanding and lots more… Will GPT-3 or an equivalent be used to deepfake human understanding?


Joscha Bach on GPT-3, achieving AGI, machine understanding and lots more
02:40 What’s missing in AI atm? Unified coherent model of reality
04:14 AI systems like GPT-3 behave as if they understand — what’s missing?
08:35 Symbol grounding — does GPT-3 have it?
09:35 GPT-3 for music generation, GPT-3 for image generation, GPT-3 for video generation
11:13 GPT-3 temperature parameter. Strange output?
13:09 GPT-3 a powerful tool for idea generation
14:05 GPT-3 as a tool for writing code. Will GPT-3 spawn a singularity?
16:32 Increasing GPT-3 input context may have a high impact
16:59 Identifying grammatical structure & language
19:46 What is the GPT-3 transformer network doing?
21:26 GPT-3 uses brute force, not zero-shot learning, humans do ZSL
22:15 Extending the GPT-3 token context space. Current Context = Working Memory. Humans with smaller current contexts integrate concepts over long time-spans
24:07 GPT-3 can’t write a good novel
25:09 GPT-3 needs to become sensitive to multi-modal sense data — video, audio, text etc
26:00 GPT-3 a universal chat-bot — conversations with God & Johann Wolfgang von Goethe
30:14 What does understanding mean? Does it have gradients (i.e. from primitive to high level)?
32:19 (correlation vs causation) What is causation? Does GPT-3 understand causation? Does GPT-3 do causation?
38:06 Deep-faking understanding
40:06 The metaphor of the Golem applied to civ
42:33 GPT-3 fine with a person in the loop. Big danger in a system which fakes understanding. Deep-faking intelligible explanations.
44:32 GPT-3 babbling at the level of non-experts
45:14 Our civilization lacks sentience — it can’t plan ahead
46:20 Would GTP-3 (a hopfield network) improve dramatically if it could consume 1 to 5 trillion parameters?
47:24 GPT3: scaling up a simple idea. Clever hacks to formulate the inputs
47:41 Google GShard with 600 billion input parameters — Amazon may be doing something similar — future experiments
49:12 Ideal grounding in machines
51:13 We live inside a story we generate about the world — no reason why GPT-3 can’t be extended to do this
52:56 Tracking the real world
54:51 MicroPsi
57:25 What is computationalism? What is it’s relationship to mathematics?
59:30 Stateless systems vs step by step Computation — Godel, Turing, the halting problem & the notion of truth
1:00:30 Truth independent from the process used to determine truth. Constraining truth that which can be computed on finite state machines
1:03:54 Infinities can’t describe a consistent reality without contradictions
1:06:04 Stevan Harnad’s understanding of computation
1:08:32 Causation / answering ‘why’ questions
1:11:12 Causation through brute forcing correlation
1:13:22 Deep learning vs shallow learning
1:14:56 Brute forcing current deep learning algorithms on a Matrioshka brain — would it wake up?
1:15:38 What is sentience? Could a plant be sentient? Are eco-systems sentient?
1:19:56 Software/OS as spirit — spiritualism vs superstition. Empirically informed spiritualism
1:23:53 Can we build AI that shares our purposes?
1:26:31 Is the cell the ultimate computronium? The purpose of control is to harness complexity
1:31:29 Intelligent design
1:33:09 Category learning & categorical perception: Models — parameters constrain each other
1:35:06 Surprise minimization & hidden states; abstraction & continuous features — predicting dynamics of parts that can be both controlled & not controlled, by changing the parts that can be controlled. Categories are a way of talking about hidden states.
1:37:29 ‘Category’ is a useful concept — gradients are often hard to compute — so compressing away gradients to focus on signals (categories) when needed
1:38:19 Scientific / decision tree thinking vs grounded common sense reasoning
1:40:00 Wisdom/common sense vs understanding. Common sense, tribal biases & group insanity. Self preservation, dunbar numbers
1:44:10 Is g factor & understanding two sides of the same coin? What is intelligence?
1:47:07 General intelligence as the result of control problems so general they require agents to become sentient
1:47:47 Solving the Turing test: asking the AI to explain intelligence. If response is an intelligible & testable implementation plan then it passes?
1:49:18 The term ‘general intelligence’ inherits it’s essence from behavioral psychology; a behaviorist black box approach to measuring capability
1:52:15 How we perceive color — natural synesthesia & induced synesthesia
1:56:37 The g factor vs understanding
1:59:24 Understanding as a mechanism to achieve goals
2:01:42 The end of science?
2:03:54 Exciting currently untestable theories/ideas (that may be testable by science once we develop the precise enough instruments). Can fundamental physics be solved by computational physics?
2:07:14 Quantum computing. Deeper substrates of the universe that runs more efficiently than the particle level of the universe?
2:10:05 The Fermi paradox
2:12:19 Existence, death and identity construction.

Sep 10, 2020

Quantum Simulations of Curved Space

Posted by in categories: computing, cosmology, mathematics, particle physics, quantum physics

A heptagonal-lattice superconducting circuit, and the mathematics that describe it, provide tools for studying quantum mechanics in curved space.

According to John Wheeler’s summary of general relativity, “space-time tells matter how to move; matter tells space-time how to curve.” How this relationship plays out at the quantum scale is not known, because extending quantum experiments to curved space poses a challenge. In 2019, Alicia Kollár and colleagues at Princeton University met that challenge with a photonic circuit that represents the negatively curved space of an expanding universe [1]. Now, Igor Boettcher and colleagues at the University of Maryland, College Park, describe those experiments with a new theoretical framework [2]. Together, the studies offer a toolkit for studying quantum mechanics in curved space that could help answer fundamental questions about cosmology.

In a universe that expands at an accelerating rate, space curves away from itself at every point, producing a saddle-like, hyperbolic geometry. To project hyperbolic space onto a plane, Kollár’s team etched a centimeter-sized chip with superconducting resonators arranged in a lattice of heptagonal tiles. By decreasing the tile size toward the edge of the chip, the researchers reproduced a perplexing property of hyperbolic space: most of its points exist on its boundary. As a result, photons moving through the circuit behave like particles moving in negatively curved space.

Sep 9, 2020

Entangled light is unscrambled using entanglement itself

Posted by in category: quantum physics

Natalia Herrera-Valencia and colleagues have successfully unscrambled entangled light after it has passed through a 2 m long multimode fibre. Led by Mehul Malik, the team at the Heriot-Watt University in Edinburgh tackled the challenge using entanglement itself. The research was done in collaboration with a colleague at the University of Glasgow and is described in a recent paper in Nature Physics.

Light passing through a disordered (or “complex”) medium like atmospheric fog or a multimode fibre gets scattered, albeit in a known manner. As a result, the information carried by the light gets distorted but is preserved, and extra steps are needed to access it. This gets especially tricky for the transport of entangled states of light because the medium muddles up the quantum correlations. The states get “scrambled” and “unscrambling” becomes necessary to retrieve the original entangled states.

Sep 9, 2020

First Photonic Quantum Computer on the Cloud

Posted by in categories: computing, quantum physics

First photonic quantum computer on the cloud.

Sep 9, 2020

Technique prevents errors in quantum computers

Posted by in categories: computing, quantum physics

Even quantum computers make mistakes. Their computing ability is extraordinary, exceeding that of classical computers by far. This is because circuits in quantum computers are based on qubits that can represent not only zeroes or ones, but also superpositions of both states by using the principles of quantum mechanics. Despite their great potential, qubits are extremely fragile and prone to errors due to the interactions with the external environment.

To solve this crucial issue, an international research group developed and implemented a new protocol that protects fragile quantum information and corrects errors due to loss. This research group published the results of their study in Nature.

“Developing a fully functioning quantum processor still represents a great challenge for scientists across the world,” explains Davide Vodola who is one of the authors of the study as well as a researcher at the University of Bologna. “This research allowed us, for the first time, to implement a protocol that can detect and, at the same time, correct errors due to qubit loss. This ability could prove to be essential for the future development of large-scale quantum computers.”

Sep 9, 2020

Gravitational crystal inside the black hole

Posted by in categories: cosmology, quantum physics

Circa 2015. What if a hull of ship could have warp crystals that could slip through space time easier.


Crystals, as quantum objects typically much larger than their lattice spacing, are a counterexample to a frequent prejudice that quantum effects should not be pronounced at macroscopic distances. We propose that the Einstein theory of gravity only describes a fluid phase and that a phase transition of crystallization can occur under extreme conditions such as those inside the black hole. Such a crystal phase with lattice spacing of the order of the Planck length offers a natural mechanism for pronounced quantum-gravity effects at distances much larger than the Planck length. A resolution of the black-hole information paradox is proposed, according to which all information is stored in a crystal-phase remnant with size and mass much above the Planck scale.

Sep 9, 2020

Terahertz receiver for 6G wireless communications

Posted by in categories: internet, quantum physics, robotics/AI

Future wireless networks of the 6th generation (6G) will consist of a multitude of small radio cells that need to be connected by broadband communication links. In this context, wireless transmission at THz frequencies represents a particularly attractive and flexible solution. Researchers at Karlsruhe Institute of Technology (KIT) have now developed a novel concept for low-cost terahertz receivers that consist of a single diode in combination with a dedicated signal processing technique. In a proof-of-concept experiment, the team demonstrated transmission at a data rate of 115 Gbit/s and a carrier frequency of 0.3 THz over a distance of 110 meters. The results are reported in Nature Photonics.

5G will be followed by 6G: The sixth generation of mobile communications promises even higher data rates, shorter latency, and strongly increased densities of terminal devices, while exploiting Artificial Intelligence (AI) to control devices or autonomous vehicles in the Internet-of-Things era. “To simultaneously serve as many users as possible and to transmit data at utmost speed, future wireless networks will consist of a large number of small radio cells,” explains Professor Christian Koos, who works on 6G technologies at KIT together with his colleague Professor Sebastian Randel. In these radio cells, distances are short such that can be transmitted with minimum energy consumption and low electromagnetic immission. The associated base stations will be compact and can easily be mounted to building facades or street lights.

To form a powerful and flexible network, these base stations need to be connected by high-speed wireless links that offer data rates of tens or even hundreds of gigabits per second (Gbit/s). This may be accomplished by terahertz carrier waves, which occupy the frequency range between microwaves and infrared light waves. However, terahertz receivers are still rather complex and expensive and often represent the bandwidht bottleneck of the entire link. In cooperation with Virginia Diodes (VDI) in Charlottesville, U.S., researchers of KIT’s Institute of Photonics and Quantum Electronics (IPQ), Institute of Microstructure Technology (IMT), and Institute for Beam Physics and Technology (IBPT) have now demonstrated a particularly simple inexpensive receiver for terahertz signals. The concept is presented in Nature Photonics.

Sep 9, 2020

Kondo physics in antiferromagnetic Weyl semimetal films

Posted by in categories: engineering, particle physics, quantum physics

Emerging quantum materials can be defined by topology and strong electron correlations, although their applications in experimental systems are relatively limited. Weyl semimetals incorporating magnetism offer a unique and fertile platform to explore emerging phenomena in developing topological matter and topological spintronics. The triangular antiferromagnet Mn3Sn exhibits many exotic physical properties as an antiferromagnetic (AFM) Weyl semimetal (WSM), including an attractively large spontaneous Hall effect.

The spontaneous Hall effect was discovered more than a century ago and understood in terms of time-reversal symmetry breaking by the internal spin structure of antiferromagnetic, ferromagnetic or skyrmionic (small swirling topological defects in the magnetization) forms.

In a new report now published on Science Advances, Durga Khadka and a team of scientists in physics, , neutron research and engineering in the U.S. reported the synthesis of epitaxial Mn3+x Sn1−x films with compositions similar to bulk samples. When they replaced the tin (Sn) atoms with magnetic manganese (Mn) atoms in the samples, they noted the Kondo effect; a celebrated example of strong correlations to emerge, then develop coherence and induce a hybridization energy gap. The process of magnetic doping and gap opening facilitated rich extraordinary properties for the new materials.