Lifeboat Foundation

Physical interpretations of the time-symmetric formulation of quantum mechanics, due to Aharonov, Bergmann, and Lebowitz are discussed in terms of weak values. The most direct, yet somewhat naive, interpretation uses the time-symmetric formulation to assign eigenvalues to unmeasured observables of a system, which results in logical paradoxes, and no clear physical picture. A top–down ontological model is introduced that treats the weak values of observables as physically real during the time between pre-and post-selection (PPS), which avoids these paradoxes. The generally delocalized rank-1 projectors of a quantum system describe its fundamental ontological elements, and the highest-rank projectors corresponding to individual localized objects describe an emergent particle model, with unusual particles, whose masses and energies may be negative or imaginary. This retrocausal top–down model leads to an intuitive particle-based ontological picture, wherein weak measurements directly probe the properties of these exotic particles, which exist whether or not they are actually measured.

Separation processes are essential in the purification and concentration of a target molecule during water purification, removal of pollutants, and heat pumping, accounting for 10–15% of global energy consumption. To make the separation processes more energy efficient, improvement in the design of porous materials is necessary. This could drastically reduce energy costs by about 40–70%. The primary approach to improving the separation performance is to precisely control the pore structure.

In this regard, porous carbon materials offer a distinct advantage as they are composed of only one type of atom and have been well-used for separation processes. They have large pore volumes and surface areas, providing high performance in gas separation, water purification, and storage. However, pore structures generally have high heterogeneity with low designability. This poses various challenges, limiting the applicability of carbon materials in separation and storage.

Now, a team of researchers from Japan, led by Associate Professor Tomonori Ohba from Chiba University and including master’s students, Mr. Kai Haraguchi and Mr. Sogo Iwakami, has fabricated fullerene-pillared porous graphene (FPPG)—a carbon composite comprising nanocarbons—using a bottom-up approach with highly designable and controllable pore structures.

The early history of laser cooling is a tale of three Nobel prizes and plenty of hard work, as Chad Orzel reveals.

Perovskite-based light emitting diodes (LEDs) could be the key to developing internet bandwidths orders of magnitude faster than what is now available, while also keeping energy consumption and cost down, researchers have claimed. Other potential applications lie in laser technology.

Perovskite is a natural mineral first identified in Russia’s Ural Mountains in 1,839 and composed primarily of calcium, titanium, and oxygen – all in the 10 most common elements in the Earth’s crust. The mineral gave its name to a class of materials based on the same elements but doped with small quantities of others. For almost the first two centuries after their discovery, these perovskites were largely a curiosity of interest only to chemists.

More recently, however, the ability of perovskites to display different electrical properties depending on the atoms with which they are doped has turned them into a wonder material. Perovskites now represent one of the most efficient ways to trap energy from sunlight and are continuing to improve at unprecedented rates. Moreover, perovskites have the potential to be manufactured far more cheaply than traditional silicon-based solar cells, while a layer of perovskite over a silicon base could capture more light than either on their own.

The Rydberg state is prevalent across various physical mediums such as atoms, molecules, and solid materials. Rydberg excitons, which are highly energized, Coulomb-bound electron-hole pair states, were initially identified in the 1950s within the semiconductor material, Cu2O.

In a study published in Science, Dr. Xu Yang and his colleagues from the Institute of Physics (IOP) of the Chinese Academy of Sciences (CAS), in collaboration with researchers led by Dr. Yuan Shengjun of Wuhan University, have reported observing Rydberg moiré excitons, which are moiré-trapped Rydberg excitons in the monolayer semiconductor WSe2 adjacent to small-angle twisted bilayer graphene.

Graphene is an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes of carbon, including graphite, charcoal, carbon nanotubes, and fullerenes. In proportion to its thickness, it is about 100 times stronger than the strongest steel.

When two particles are entangled, the state of one is tied to the state of the other.

A long-standing challenge in the field of quantum physics is the efficient synchronization of individual and independently generated photons (i.e., light particles). Realizing this would have crucial implications for quantum information processing that relies on interactions between multiple photons.

Researchers at Weizmann Institute of Science recently demonstrated the synchronization of single, independently generated photons using an atomic quantum memory operating at room-temperature. Their paper, published in Physical Review Letters, could open new avenues for the study of multi-photon states and their use in quantum information processing.

“The project idea came about several years ago, when our group and the group of Ian Walmsley demonstrated an atomic quantum memory with an inverted atomic-level scheme compared to the typical memories—the ladder memory, named fast ladder memory (FLAME),” Omri Davidson, one of the researchers who carried out the study, told Phys.org. “These memories are fast and noise-free, and therefore they are useful for synchronization of single photons.”

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An international team of scientists has succeeded in experimentally confirming a characteristic of topological materials.

Scientists from around the globe have experimentally confirmed a unique characteristic of topological materials. Using ‘3D glasses’-like technology and particle accelerators, they successfully visualized the relationship between an electron’s topology and its quantum mechanical properties, marking a significant step forward in understanding these future-focused materials.

Topological quantum materials are seen as a beacon of hope for energy-saving electronics and the high-tech of the future. A defining feature of these materials is their ability to conduct spin-polarized electrons on their surface, while remaining non-conductive inside. To put this into perspective: In spin-polarized electrons, the intrinsic angular momentum, i.e. the direction of rotation of the particles (spin), is not purely randomly aligned.