Lifeboat Foundation

Photosynthesis is the process that plants, algae, and even certain species of bacteria use to convert sunlight into oxygen and chemical energy stored as sugar (aka gluclose). But what are the mechanisms behind one of nature’s most profound processes?

These are questions that a team of researchers led by the Ludwig Maximilian University of Munich (LMU) hope to answer as they used quantum chemical calculations to examine a photosynthesis protein complex known as photosystem I (PSI) in hopes of better understanding the complete process of photosynthesis and how plants are able to convert sunlight to energy, specifically pertaining to how chlorophylls and the reaction center play their roles in the process.

Researchers from Colorado State University and the Colorado School of Mines have thought up a new computational imaging strategy that exploits the best of both the quantum and classical worlds. They developed an efficient and robust algorithm that fuses quantum and classical information for high-quality imaging. The results of their research were published Dec. 21 in Intelligent Computing.

Recently, the quantum properties of light have been exploited to enable super resolution microscopy. While quantum information brings new possibilities, it has its own set of limitations.

The researchers’ approach is based on classical and quantum correlation functions obtained from photon counts, which are collected from quantum emitters illuminated by spatiotemporally structured illumination. Photon counts are processed and converted into signals of increasing order, which contain increasing spatial frequency information. The higher spatial resolution information, however, suffers from a reduced signal-to-noise ratio at increasingly larger correlation orders.

Deyi Li from the Chinese Association for Artificial Intelligence believes that humans and machines have a mutually beneficial relationship.

His paper on machine intelligence, which was published in Intelligent Computing, builds on five groundbreaking works by Schrödinger, the father of quantum mechanics, Turing, the father of artificial intelligence, and Wiener, the father of cybernetics.

Inspired by Schrödinger’s book “What is Life? The Physical Aspect of the Living Cell,” Li believes that machines can be considered living things. That is, like humans, they decrease the amount of entropy or disorder in their environment through their interactions with the world.

University of Texas at Dallas researchers have developed a new approach that addresses challenges in the field of quantum computing and has the potential to revolutionize computing, communications and electronic security.

To make solid-state qubits, the basic information unit for quantum computers, a defect must be inserted into the solid material to control the spin states of electrons. Creating and positioning the defect, however, especially in the most commonly used solid material—synthetic diamonds —poses a major challenge.

UT Dallas researchers found that making qubits from thin, two-dimensional sheets of crystals called transition metal dichalcogenides (TMDs) instead of diamond can solve this problem. Led by Dr. Kyeongjae Cho, professor of materials science and engineering in the Erik Jonsson School of Engineering and Computer Science, the researchers published their findings online Dec. 6 in Nature Communications.

Scientists at the University of Groningen used a silver sawtooth nanoslit array to produce valley-coherent photoluminescence in two-dimensional tungsten disulfide flakes at room temperature. Until now, this could only be achieved at very low temperatures. Coherent light can be used to store or transfer information in quantum electronics. This plasmon-exciton hybrid device is promising for use in integrated nanophotonics (light-based electronics). The results were published in Nature Communications on 5 February.

Tungsten disulfide has interesting electronic properties and is available as a 2-D material. “The electronic structure of monolayer tungsten disulfide shows two sets of lowest energy points or valleys,” explains Associate Professor Justin Ye, head of the Device Physics of Complex Materials group at the University of Groningen. One possible application is in photonics, as it can emit light with valley-dependent circular polarization—a new degree of freedom to manipulate information. However, valleytronics requires coherent and polarized light. Unfortunately, previous work showed that photoluminescence polarization in tungsten disulfide is almost random at room temperature.

A team of chemists, engineers, material scientists and physicists from Princeton University, Rutgers University and the University of Regensburg has developed a chemical exfoliation technique to produce single-molecule-thick tungsten disulfide ink. The group describes their technique in a paper published in the journal Science Advances.

As research continues into the creation of truly useful quantum computers, scientists continue to search for new materials that could support such machines. In this new effort, the research team looked into finding ways to print very cold circuits inside quantum computers using superconducting ink.

The new method involved a material consisting of layers of tungsten disulfide and potassium. The researchers exfoliated the material by dunking it into a sulfuric acid solution. This dissolved the potassium and left behind single-molecule layers of tungsten disulfide. The final step involved rinsing the acid and remnants in it, leaving the layers of tungsten suspended in a tub of water. In this state, the researchers found that the layers of tungsten disulfide could be used as a form of ink that could be printed onto various types of surfaces, such as plastic, silicon or glass. This left a one-molecule-thick coating on the material.

Researchers have succeeded in creating an efficient quantum-mechanical light-matter interface using a microscopic cavity. Within this cavity, a single photon is emitted and absorbed up to 10 times by an artificial atom. This opens up new prospects for quantum technology, report physicists at the University of Basel and Ruhr-University Bochum in the journal Nature.

Quantum physics describes photons as light particles. Achieving an interaction between a single photon and a single atom is a huge challenge due to the tiny size of the atom. However, sending the photon past the atom several times by means of mirrors significantly increases the probability of an interaction.

In order to generate photons, the researchers use artificial atoms, known as quantum dots. These semiconductor structures consist of an accumulation of tens of thousands of atoms, but behave much like a single atom: when they are optically excited, their energy state changes and they emit a photon. “However, they have the technological advantage that they can be embedded in a semiconductor chip,” says Dr. Daniel Najer, who conducted the experiment at the Department of Physics at the University of Basel.

Supercomputers and quantum computers are potent tools for handling difficult calculations, problem-solving, and data analysis. Although they both have the potential to transform computing technology, their speeds and capacities differ greatly.

Supercomputers quickly process massive volumes of data to provide a single result using a conventional computing strategy with numerous processors. These computers are the most powerful in terms of raw computing speed, but they can only do one task at a time, and Moore’s Law places a cap on how much data they can process (the principle that computer processor speeds double every two years).

Quantum computers, on the other hand, utilize laws of quantum mechanics to process information in ways that regular computers cannot, resulting in vastly higher processing speeds. They can manage several activities at once and take on challenging issues that would take supercomputer months to resolve. Yet, because of their great sensitivity to temperature fluctuations and need for isolation from outside influences, quantum computers require more upkeep than their conventional equivalents.

In a mind-warping milestone experiment, scientists have been able to manipulate small numbers of individual photons of light, opening doors for the development of quantum technologies. This research, published in the journal Nature Physics on March 20, describes how the researchers were able to make two photons of light interact and measure the difference between these interacting photons and a single photon.