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Archive for the ‘quantum physics’ category: Page 207

Sep 26, 2023

MIT researchers develop circuit to improve quantum computing

Posted by in categories: quantum physics, supercomputing

The team achieved 99.99 percent accuracy with a single-qubit gate and 99.9 percent accuracy with a two-qubit gate.

Researchers at the Massachusetts Institute of Technology (MIT) have developed a new circuit that can do quantum computation with a high degree of accuracy. The researchers used a new type of superconducting qubit called the fluxonium, a press release said.

Quantum computers are considered the next frontier of computing since they can perform calculations at speeds that are decades ahead of supercomputers being used today. The flip side of such high speeds is that they can accumulate errors equally fast.

Sep 26, 2023

Two Black Holes Masquerading as One

Posted by in categories: cosmology, information science, quantum physics

Black holes may be less unique than previously thought, as the expansion due to a cosmological constant can hold apart a pair of holes and allow them to mimic a single black hole.

Black holes are astonishing objects that can pack the mass of Earth into a space the size of a pea. A remarkable attribute is their stunning simplicity, which is encapsulated in the celebrated uniqueness theorems [1]. Briefly stated, these theorems say that there is only one solution to Einstein’s equations of general relativity for a fully collapsed (nonevolving) system having fixed mass and angular momentum [2]. The implication is that all black holes that have settled down to equilibrium with the same mass and rotation are precisely the same: their entire behavior described by a single equation—the so-called Kerr solution—filling only a few lines of paper!

But there is a catch. The uniqueness theorems make a number of assumptions, the key one being that the space around the black hole is “empty”—in other words, there is no energy that might influence the black hole. Such energy can arise from fields, for example, those of the standard model, or from a “cosmological constant,” which is a form of dark energy that might be behind the accelerated expansion of our Universe today. In a fascinating study, Óscar Dias from the University of Southampton, UK, and colleagues demonstrate that uniqueness is violated in the presence of a positive cosmological constant [3]. Specifically, they show that a pair of black holes whose mutual attraction is balanced by the cosmic expansion would look the same to a distant observer as a single isolated black hole. The results may lead to a rethinking of how simple black holes really are.

Sep 26, 2023

Using quantum materials as catalysts for fertilizer synthesis

Posted by in categories: food, quantum physics

Synthetic fertilizers, one the most important developments in modern agriculture, have enabled many countries to secure a stable food supply. Among them, organic ureas (or organoureas) have become prominent sources of nitrogen for crops. Since these compounds do not dissolve immediately in water, but instead are slowly decomposed by soil microorganisms, they provide a stable and controlled supply of nitrogen, which is crucial for plant growth and function.

However, traditional methods to synthesize organoureas are environmentally harmful due to their use of toxic substances, such as phosgene. Although alternative synthesis strategies have been demonstrated, these either rely on expensive and scarce noble metals or employ catalysts that cannot be reused easily.

In a recent effort to address these challenges, a research team including Honorary Professor Hideo Hosono from Tokyo Institute of Technology, Japan, has leveraged the quantum properties of bismuth selenide (Bi2Se3) to synthesize organoureas. Their study is published in Science Advances.

Sep 25, 2023

Canceling Noise: MIT’s Innovative Way To Boost Quantum Devices

Posted by in categories: computing, education, engineering, quantum physics

For years, researchers have tried various ways to coax quantum bits — or qubits, the basic building blocks of quantum computers — to remain in their quantum state for ever-longer times, a key step in creating devices like quantum sensors, gyroscopes, and memories.

A team of physicists from MIT

MIT is an acronym for the Massachusetts Institute of Technology. It is a prestigious private research university in Cambridge, Massachusetts that was founded in 1861. It is organized into five Schools: architecture and planning; engineering; humanities, arts, and social sciences; management; and science. MIT’s impact includes many scientific breakthroughs and technological advances. Their stated goal is to make a better world through education, research, and innovation.

Sep 23, 2023

Exploring the relationship between thermalization dynamics and quantum criticality in lattice gauge theories

Posted by in categories: information science, particle physics, quantum physics

Researchers from the University of Science and Technology of China(USTC) of the Chinese Academy of Sciences (CAS) have developed an ultra-cold atom quantum simulator to study the relationship between the non-equilibrium thermalization process and quantum criticality in lattice gauge field theories. The research was led by Pan Jianwei and Yuan Zhensheng, in collaboration with Zhai Hui from Tsinghua University and Yao Zhiyuan from Lanzhou University.

Their findings reveal that multi-body systems possessing gauge symmetry tend to thermalize to an equilibrium state more easily when situated in a critical region. The results were published in Physical Review Letters.

Gauge and are two foundational theories of physics. From the Maxwell’s equations of classical electromagnetism to and the Standard Model, which describe the interactions of fundamental particles, all adhere to specific gauge symmetries. On the other hand, statistical mechanics connects the microscopic states of large ensembles of particles (such as atoms and molecules) to their macroscopic statistical behaviors, based on the principle of maximum entropy proposed by Boltzmann and others. It elucidates, for instance, how the energy distribution of microscopic particles affects macroscopic quantities like pressure, volume, or temperature.

Sep 22, 2023

SLAC fires up the world’s most powerful X-ray laser: LCLS-II ushers in a new era of science

Posted by in categories: biological, chemistry, computing, quantum physics, science, sustainability

The newly upgraded Linac Coherent Light Source (LCLS) X-ray free-electron laser (XFEL) at the Department of Energy’s SLAC National Accelerator Laboratory successfully produced its first X-rays, and researchers around the world are already lined up to kick off an ambitious science program.

The upgrade, called LCLS-II, creates unparalleled capabilities that will usher in a new era in research with X-rays.

Scientists will be able to examine the details of quantum materials with unprecedented resolution to drive new forms of computing and communications; reveal unpredictable and fleeting chemical events to teach us how to create more sustainable industries and ; study how carry out life’s functions to develop new types of pharmaceuticals; and study the world on the fastest timescales to open up entirely new fields of scientific investigation.

Sep 22, 2023

Engineers develop enhanced GaN-based LED array visible light communication system

Posted by in categories: energy, internet, quantum physics

Under the limitation of current density, micro-LED is difficult to achieve watts level optical power, which is not suitable for long-distance and underwater optical communication that requires high-power optical transmitter devices. Therefore, how to improve the communication performance of conventional-size LED is also a key issue at present.

The authors of an article published in Opto-Electronic Science studied a wavelength division multiplexing visible light communication system based on multi-color LED. The system uses a Si substrate GaN-based LED with a 3D structured quantum well. In the active layer of this LED, there is a three-dimensional structure (“V” shaped pit, or V-pit) with a hexagonal profile, opening towards the P-type GaN layer.


With the large-scale commercial use of 5G, global academia and industry have started research on the next-generation mobile communication technology (6G).

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Sep 22, 2023

How can quantum computers be better than classical computers?

Posted by in categories: quantum physics, robotics/AI

Scientists have been exploring both experimental and theoretical ways to prove quantum supremacy.

Ramis Movassagh, a researcher at Google Quantum AI, recently had a study published in the journal Nature Physics. Here, he has reportedly demonstrated in theory that simulating random quantum circuits and determining their output will be extremely difficult for classical computers. In other words, if a quantum computer solves this problem, it can achieve quantum supremacy.

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Sep 21, 2023

Intel Plans a Quantum Computing Approach to Leapfrog Rivals

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

The chipmaker is developing a sequel to its Tunnel Falls quantum processor. Quantum computing in coming years could improve batteries, finance and AI.

Sep 20, 2023

First Light for a Next-Generation Light Source

Posted by in categories: biological, chemistry, nanotechnology, particle physics, quantum physics

X-ray free-electron lasers (XFELs) first came into existence two decades ago. They have since enabled pioneering experiments that “see” both the ultrafast and the ultrasmall. Existing devices typically generate short and intense x-ray pulses at a rate of around 100 x-ray pulses per second. But one of these facilities, the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory in California, is set to eclipse this pulse rate. The LCLS Collaboration has now announced “first light” for its upgraded machine, LCLS-II. When it is fully up and running, LCLS-II is expected to fire one million pulses per second, making it the world’s most powerful x-ray laser.

The LCLS-II upgrade signifies a quantum leap in the machine’s potential for discovery, says Robert Schoenlein, the LCLS’s deputy director for science. Now, rather than “demonstration” experiments on simple, model systems, scientists will be able to explore complex, real-world systems, he adds. For example, experimenters could peer into biological systems at ambient temperatures and physiological conditions, study photochemical systems and catalysts under the conditions in which they operate, and monitor nanoscale fluctuations of the electronic and magnetic correlations thought to govern the behavior of quantum materials.

The XFEL was first proposed in 1992 to tackle the challenge of building an x-ray laser. Conventional laser schemes excite large numbers of atoms into states from which they emit light. But excited states with energies corresponding to x-ray wavelengths are too short-lived to build up a sizeable excited-state population. XFELs instead rely on electrons traveling at relativistic speed through a periodic magnetic array called an undulator. Moving in a bunch, the electrons wiggle through the undulator, emitting x-ray radiation that interacts multiple times with the bunch and becomes amplified. The result is a bright x-ray beam with laser coherence.