Lifeboat Foundation

To create large quantum networks, researchers will first need to develop efficient quantum repeaters. A key component of these repeaters are quantum memories, which are the quantum-mechanical equivalents of more conventional computer memories, such as random-access memories (RAM).

Ideally, a quantum memory should be able to retain information for substantial periods of time, store true quantum states, read out data efficiently and operate at low-loss telecommunication wavelengths. While research teams have made great progress in the development of quantum memories, no solution proposed so far has been able to meet all of these requirements simultaneously.

With this in mind, researchers at Delft University of Technology (TU Delft) set out to develop a new mechanical quantum memory with sufficiently long storage times, a high readout efficiency, and the ability to operate at telecom wavelengths. The memory they devised, presented in a paper published in Nature Physics, could ultimately enable the practical implementation of mechanical systems with quantum effects developed in their previous works.

Rational design of compounds with specific properties requires understanding and fast evaluation of molecular properties throughout chemical compound space — the huge set of all potentially stable molecules. Recent advances in combining quantum-mechanical calculations with machine learning provide powerful tools for exploring wide swathes of chemical compound space. We present our perspective on this exciting and quickly developing field by discussing key advances in the development and applications of quantum-mechanics-based machine-learning methods to diverse compounds and properties, and outlining the challenges ahead. We argue that significant progress in the exploration and understanding of chemical compound space can be made through a systematic combination of rigorous physical theories, comprehensive synthetic data sets of microscopic and macroscopic properties, and modern machine-learning methods that account for physical and chemical knowledge.

Fascinating talk on a fun topic.

How does quantum logic differ from classical logic? How do we live in a universe that accommodates both?
Is it possible to observe quantum logic at work in our macroscopic world?
Surprisingly a little bit of quantum logic can disentangle some of our clumsy everyday conceptualisations of biology, language and culture.

Continue reading “Chris Guest — Quantum Logic & the Rise of the Memes” »

It’s easy to take time’s arrow for granted — but the gears of physics actually work just as smoothly in reverse. Maybe that time machine is possible after all?

An experiment from 2019 shows just how much wiggle room we can expect when it comes to distinguishing the past from the future, at least on a quantum scale. It might not allow us to relive the 1960s, but it could help us better understand why not.

Researchers from Russia and the US teamed up to find a way to break, or at least bend, one of physics’ most fundamental laws of energy.

Paris (AFP) — Scientists have observed the fifth state of matter in space for the first time, offering unprecedented insight that could help solve some of the quantum universe’s most intractable conundrums, research showed Thursday.

Bose-Einstein condensates (BECs) — the existence of which was predicted by Albert Einstein and Indian mathematician Satyendra Nath Bose almost a century ago — are formed when atoms of certain elements are cooled to near absolute zero (0 Kelvin, minus 273.15 Celsius).

At this point, the atoms become a single entity with quantum properties, wherein each particle also functions as a wave of matter.

Electrons are very much at the mercy of magnetic fields, which scientists can manipulate to control the electrons and their angular momentum—i.e. their “spin.”

A Cornell team led by Greg Fuchs, assistant professor of applied and engineering physics in the College of Engineering, in 2013 invented a new way to exert this control by using acoustic waves generated by mechanical resonators. That approach enabled the team to control electron spin transitions (also known as spin resonance) that otherwise wouldn’t be possible through conventional magnetic behavior.

The finding was a boon for anyone looking to build quantum sensors of the sort used in mobile navigation devices. However, such devices still required a magnetic control field—and therefore a bulky magnetic antenna—to drive certain spin transitions.

Plug And Play

The underlying mechanics of a quantum computer won’t be any less difficult to comprehend under Gil’s vision of the future. But, he argues, it won’t matter because programming quantum computing software would become far more automated along the way.

“You’ll simply have to write a line of code in any programming language you work with,” Gil wrote, “and the system will match it with the circuit in the library and the right quantum computer.”

Mobile phones and computers are currently responsible for up to 8% of the electricity use in the world. This figure has been doubling each past decade but nothing prevents it from skyrocketing in the future. Unless we find a way for boosting energy efficiency in information and communications technology, that is. An international team of researchers, including Ikerbasque Research Associate Alexey Nikitin (DIPC), has just published in Nature ¹ a breakthrough in quantum physics that could deliver exactly that: electronics and communications technology with ultralow energy consumption.

Future information and communication technologies will rely on the manipulation of not only electrons but also of light at the nanometer-scale. Squeezing light to such a small size has been a major goal in nanophotonics for many years. Particularly strong light squeezing can be achieved with polaritons, quasiparticles resulting from the strong coupling of photons with a dipole-carrying excitation, at infrared frequencies in two-dimensional materials, such as graphene and hexagonal boron nitride. Polaritons can be found in materials consisting of two-dimensional layers bound by weak van der Waals forces, the so-called van der Waals materials. These polaritons can be tuned by electric fields or by adjusting the material thickness, leading to applications including nanolasers, tunable infrared and terahertz detectors, and molecular sensors.

But there is a major problem: even though polaritons can have long lifetimes, they have always been found to propagate along all directions (isotropic) of the material surface, thereby losing energy quite fast, which limits their application potential.

Quantum computing is still the province of specialized programmers—but that is likely to change very quickly.