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Archive for the ‘quantum physics’ category: Page 217

Oct 27, 2023

From Russia With Theory: Landau’s Quasiparticles Come to Life

Posted by in categories: particle physics, quantum physics

Physicists, building on Lev Landau’s theory of quasiparticles, used ultracold quantum gases to simulate electron behavior in solids. Their recent experiment revealed that these quasiparticles can have both attractive and repulsive interactions, underscoring the significance of quantum statistics.

An electron moving through a solid generates a polarization in its environment due to its electric charge. In his theoretical considerations, the Russian physicist Lev Landau extended the description of such particles by their interaction with the environment and spoke of quasiparticles. More than ten years ago, the team led by Rudolf Grimm at the Institute of Quantum Optics and Quantum Information (IQQOI) of the Austrian Academy of Sciences (ÖAW) and the Department of Experimental Physics of the University of Innsbruck succeeded in generating such quasiparticles for both attractive and repulsive interactions with the environment.

For this purpose, the scientists use an ultracold quantum gas consisting of lithium and potassium atoms in a vacuum chamber. With the help of magnetic fields, they control the interactions between the particles, and by means of radio-frequency pulses push the potassium atoms into a state in which they attract or repel the lithium atoms surrounding them. In this way, the researchers simulate a complex state similar to the one produced in the solid state by a free electron.

Oct 27, 2023

Using sound to test devices, control qubits

Posted by in categories: mobile phones, quantum physics

Acoustic resonators are everywhere. In fact, there is a good chance you’re holding one in your hand right now. Most smart phones today use bulk acoustic resonators as radio frequency filters to filter out noise that could degrade a signal. These filters are also used in most Wi-Fi and GPS systems.

Acoustic resonators are more stable than their electrical counterparts, but they can degrade over time. There is currently no easy way to actively monitor and analyze the degradation of the material quality of these widely used devices.

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in collaboration with researchers at the OxideMEMS Lab at Purdue University, have developed a system that uses atomic vacancies in to measure the stability and quality of acoustic resonators. What’s more, these vacancies could also be used for acoustically-controlled quantum information processing, providing a new way to manipulate quantum states embedded in this commonly-used material.

Oct 27, 2023

New quantum computing architecture achieves electron charge qubit with 0.1 millisecond coherence time

Posted by in categories: computing, quantum physics

Coherence stands as a pillar of effective communication, whether it is in writing, speaking or information processing. This principle extends to quantum bits, or qubits, the building blocks of quantum computing. A quantum computer could one day tackle previously insurmountable challenges in climate prediction, material design, drug discovery and more.

A team led by the U.S. Department of Energy’s (DOE) Argonne National Laboratory has achieved a major milestone toward future quantum computing. They have extended the time for their novel type of qubit to an impressive 0.1 milliseconds—nearly a thousand times better than the previous record.

The research was published in Nature Physics.

Oct 26, 2023

Atom Computing Says Its New Quantum Computer Has Over 1,000 Qubits

Posted by in categories: computing, military, particle physics, quantum physics

The scale of quantum computers is growing quickly. In 2022, IBM took the top spot with its 433-qubit Osprey chip. Yesterday, Atom Computing announced they’ve one-upped IBM with a 1,180-qubit neutral atom quantum computer.

The new machine runs on a tiny grid of atoms held in place and manipulated by lasers in a vacuum chamber. The company’s first 100-qubit prototype was a 10-by-10 grid of strontium atoms. The new system is a 35-by-35 grid of ytterbium atoms (shown above). (The machine has space for 1,225 atoms, but Atom has so far run tests with 1,180.)

Quantum computing researchers are working on a range of qubits—the quantum equivalent of bits represented by transistors in traditional computing—including tiny superconducting loops of wire (Google and IBM), trapped ions (IonQ), and photons, among others. But Atom Computing and other companies, like QuEra, believe neutral atoms—that is, atoms with no electric charge—have greater potential to scale.

Oct 25, 2023

Magnetic Coulomb Phase in the Spin Ice Ho2Ti2O7

Posted by in category: quantum physics

Year 2009 This is actually proof of string theory existence through magnetic monopoles.


Neutron scattering measurements on two spin-ice compounds show evidence for magnetic monopoles.

Oct 25, 2023

LIGO successfully squeezes quantum states, surpassing Heisenberg’s limits

Posted by in category: quantum physics

There’s a quantum limit to how precisely anything can be measured. By squeezing light, LIGO has now surpassed all previous limitations.

Oct 25, 2023

The physicist trying to create space-time from scratch

Posted by in categories: holograms, quantum physics

Monika Schleier-Smith is testing the idea that space-time emerges, like a hologram, from quantum interactions by attempting to make it in the lab.

By Lyndie Chiou

Oct 25, 2023

How this Turing Award–winning researcher became a legendary academic advisor

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

Every academic field has its superstars. But a rare few achieve superstardom not just by demonstrating individual excellence but also by consistently producing future superstars. A notable example of such a legendary doctoral advisor is the Princeton physicist John Archibald Wheeler. A dissertation was once written about his mentorship, and he advised Richard Feynman, Kip Thorne, Hugh Everett (who proposed the “many worlds” theory of quantum mechanics), and a host of others who could collectively staff a top-tier physics department. In ecology, there is Bob Paine, who discovered that certain “keystone species” have an outsize impact on the environment and started a lineage of influential ecologists. And in journalism, there is John McPhee, who has taught generations of accomplished journalists at Princeton since 1975.

Computer science has its own such figure: Manuel Blum, who won the 1995 Turing Award—the Nobel Prize of computer science. Blum’s métier is theoretical computer science, a field that often escapes the general public’s radar. But you certainly have come across one of Blum’s creations: the “Completely Automated Public Turing test to tell Computers and Humans Apart,” better known as the captcha—a test designed to distinguish humans from bots online.

Oct 25, 2023

Topological quantum computation on supersymmetric spin chains

Posted by in categories: computing, quantum physics

Only theoretical now but someday this could lead to lag free and error free quantum computers.


Quantum gates built out of braid group elements form the building blocks of topological quantum computation. They have been extensively studied in SUk quantum group theories, a rich source of examples of non-Abelian anyons such as the Ising (k = 2), Fibonacci (k = 3) and Jones-Kauffman (k = 4) anyons. We show that the fusion spaces of these anyonic systems can be precisely mapped to the product state zero modes of certain Nicolai-like supersymmetric spin chains. As a result, we can realize the braid group in terms of the product state zero modes of these supersymmetric systems. These operators kill all the other states in the Hilbert space, thus preventing the occurrence of errors while processing information, making them suitable for quantum computing.

Oct 25, 2023

Record-breaking quantum computer has more than 1000 qubits

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

Atom Computing has created the first quantum computer to surpass 1,000 qubits, which could improve the accuracy of the machines.

By Alex Wilkins