Lifeboat Foundation

The minuscule fluctuations of seemingly empty space can be controlled just enough to make the building blocks of a new type of computer.

By Karmela Padavic-Callaghan

An international team of researchers, including members from the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), has succeeded in a proof-of-principle experiment to verify strong-field quantum electrodynamics within exotic atoms, according to a recent study published in Physical Review Letters.

Physical Review Letters (PRL) is a peer-reviewed scientific journal published by the American Physical Society. It is one of the most prestigious and influential journals in physics, with a high impact factor and a reputation for publishing groundbreaking research in all areas of physics, from particle physics to condensed matter physics and beyond. PRL is known for its rigorous standards and short article format, with a maximum length of four pages, making it an important venue for rapid communication of new findings and ideas in the physics community.

An interdisciplinary team at the Advanced Quantum Testbed (AQT) at Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley’s Quantum Nanoelectronics Laboratory (QNL) achieved a technical breakthrough using qutrits—three-level systems—on a superconducting quantum processor.

The team successfully entangled two transmon qutrits with gate fidelities significantly higher than in previously reported works, thus getting closer to enabling ternary logic that can encode more information than their binary counterparts—qubits.

Published in Nature Communications in December 2022 and featured as an editor’s highlight, this experimental success pushes forward AQT’s qutrit research and development, including previous experimental successes published in 2021 in Physical Review X and Physical Review Letters. Ternary quantum information processors offer significant potential advantages in quantum simulation and error correction, as well as the ability to improve certain quantum algorithms and applications.

IVO Ltd. believes its new ‘Quantum Drive’ defies the laws of motion, and it aims to put it to the test by sending it to orbit on a SpaceX rocket.

US company IVO Ltd., a wireless power technology firm, is set to send an all-electric propulsion system for satellites to space for the first time in October.

Continue reading “Quantum drive that draws ‘limitless power’ from Sun will fly to orbit this year” »

Physicists at Harvard University in the US have created a novel strongly interacting quantum liquid known as a Laughlin state in a gas of ultracold atoms for the first time. The state, which is an example of a fractional quantum Hall (FQH) state, had previously been seen in condensed-matter systems and in photons, but observations in atoms had been elusive due to stringent experimental requirements. Because atomic systems are simpler than their condensed-matter counterparts, the result could lead to fresh insights into fundamental physics.

“Some of the most intriguing phenomena in condensed-matter physics emerge when you confine electrons in two dimensions and apply a strong magnetic field,” explains Julian Léonard, a postdoctoral researcher in the Rubidium Lab at Harvard and the lead author of a paper in Nature on the new work. “For example, the particles can behave collectively as if they have a charge that is only a fraction of the elementary charge – something that does not occur anywhere else in nature and is even ruled out by the Standard Model for all fundamental particles.”

The way in which such fractional charges arise is still not fully understood because it is difficult to study solid-state systems at an atomic scale. This is why it is so desirable to study the behaviour of FQHs in synthetic quantum systems such as cold atoms, which act as quantum simulators for more complex condensed-matter phenomena.

The future of electronics will be based on novel kinds of materials. Sometimes, however, the naturally occurring topology of atoms makes it difficult for new physical effects to be created. To tackle this problem, researchers at the University of Zurich have now successfully designed superconductors one atom at a time, creating new states of matter.

What will the computer of the future look like? How will it work? The search for answers to these questions is a major driver of basic physical research. There are several possible scenarios, ranging from the further development of classical electronics to neuromorphic computing and quantum computers.

The common element in all these approaches is that they are based on novel physical effects, some of which have so far only been predicted in theory. Researchers go to great lengths and use state-of-the-art equipment in their quest for new quantum materials that will enable them to create such effects. But what if there are no suitable materials that occur naturally?

A team at the National Institute of Standards and Technology in Boulder, Colorado, has reported the successful implementation of a 400,000 pixel superconducting nanowire single-photon detector (SNSPD) that they say will pave the way for the development of extremely light-sensitive large-format superconducting cameras. The camera will also prove invaluable for those doing medical research, where the ability to examine organs such as the brain without disturbing tissue is critical.

Superconducting detectors operate at very low temperatures and generate a minimum of excess noise, making them ideal for testing the non-local nature of reality, investigating dark matter, mapping the early universe, and performing quantum computation and communication. Previously there were no large-scale superconducting cameras – even the largest demonstrations have never exceeded 20 thousand pixels.

This was especially true for one of the most promising detector technologies, the superconducting nanowire single-photon detector (SNSPD). These detectors have been demonstrated with system detection efficiencies of 98.0%, sub-3-ps timing jitter, sensitivity from the ultraviolet (250nm) to the mid-infrared (10um), and dark count rates below 6.2e-6 counts per second (cps), but despite more than two decades of development they have never achieved an array size larger than a kilopixel. Here, we report on the implementation and characterization of a 400,000 pixel SNSPD camera, a factor of 400 improvement over the previous state-of-the-art. The array spanned an area 4×2.5 mm with a 5x5um resolution, reached unity quantum efficiency at wavelengths of 370 nm and 635 nm, counted at a rate of 1.1e5 cps, and had a dark count rate of 1e-4 cps per detector (corresponding to 0.13 cps over the whole array).

One of the most basic assumptions of fundamental physics is that the different properties of mass—weight, inertia and gravitation—always remain the same in relation to each other. Without this equivalence, Einstein’s theory of relativity would be contradicted and our current physics textbooks would have to be rewritten. Although all measurements to date confirm the equivalence principle, quantum theory postulates that there should be a violation.

This inconsistency between Einstein’s gravitational theory and modern quantum theory is the reason why ever more precise tests of the equivalence principle are particularly important. A team from the Center of Applied Space Technology and Microgravity (ZARM) at University of Bremen, in collaboration with the Institute of Geodesy (IfE) at Leibniz University Hannover, has now succeeded in proving with 100 times greater accuracy that passive gravitational mass and active gravitational mass are always equivalent—regardless of the particular composition of the respective masses.

The research was conducted within the framework of the Cluster of Excellence “QuantumFrontiers.” Today, the team published their findings as a highlights article in Physical Review Letters.

Quantum computing holds the potential to tackle complex issues in fields like material science and cryptography, problems that will remain out of reach even for the most powerful conventional supercomputers in the future. However, accomplishing this feat will likely necessitate millions of high-quality qubits, given the error correction needed.

Progress in superconducting processors advances quickly with a current qubit count in the few hundreds. The appeal of this technology lies in its swift computational speed and compatibility with microchip fabrication. However, the requirement for extremely low temperatures places a limit on the processor’s size and prevents any physical access once it is cooled down.

A modular quantum computer with multiple separately cooled processor nodes could solve this. However, single microwave photons—the particles of light that are the native information carriers between superconducting qubits within the processors—are not suitable to be sent through a room temperature environment between the processors. The world at room temperature is bustling with heat, which easily disturbs the microwave photons and their fragile quantum properties like entanglement.