Lifeboat Foundation

One of the most remarkable features discovered in these experiments is the unprecedented tunability of the two-photon state, achieved by manipulating the LC molecular orientation. By re-orienting the molecules through the application of an electric field, we can dynamically switch the polarization state of the generated photon pairs. This level of control over the photon pairs’ polarization properties is a crucial advancement, offering opportunities for quantum-state engineering in the sources with pixelwise-tunable optical properties, both linear and nonlinear.

Alternatively, we can manipulate the polarization state by implementing a molecular orientation twist along the sample. This approach adds versatility to the design and utilization of LC-based photon-pair sources. Moreover, a strong twist along the sample can markedly increase the efficiency of a macroscopically large source, similar to the periodic poling of bulk crystals and waveguides, but much simpler technologically, as the structure is self-assembled and may be tuned with temperature and electric field³⁹. Owing to their nonlinear coefficient comparable to the best nonlinear crystals, such as lithium niobate, and high damage threshold, FNLCs are perfectly suitable for practical applications. Furthermore, high-quality LC devices such as LC displays are made on an industrial scale, which, combined with our work, opens a path to scalable and cheap production of quantum light sources while exceeding the existing ones in efficiency and functionality.

In the future, the electric-field tuning could be expanded to multi-pixel devices, which have the potential to generate tunable high-dimensional entanglement and multiphoton states. Furthermore, FNLCs can self-assemble in a variety of complex topological structures, which are expected to emit photon pairs in complex, spatially varying beams (structured light), such as vector and vortex beams⁴⁰. The liquid nature of FNLCs opens a path to their integration with existing optical platforms such as fibres⁴¹, waveguides⁴² and metasurfaces⁴³.

Scientists have advanced quantum teleportation by mitigating noise interference through a novel method involving hybrid entanglement, achieving close to 90% fidelity in teleporting quantum states, which could significantly enhance secure quantum communication.

A research team led by Academician Guangcan Guo from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), in collaboration with the research team at the University of Turku, Finland, successfully overcame environmental noise to achieve high-fidelity quantum teleportation by utilizing multipartite hybrid entanglement. Their findings were published recently in the journal Science Advances.

Overcoming Challenges in Quantum Teleportation.

A study published in Nano Letters demonstrates the use of quantum dots to create metasurfaces, enabling two objects to exist in the same space.

The exact empirical evidence for retrocausality does not exist yet, but the existing empirical data as those from Bell tests may be interpreted in a way to support the retrocausal framework.

Have you ever thought that future states could affect the events that have occurred in the past? Although this idea sounds quite bizarre, it is indeed possible according to a quantum mechanical effect called retrocausality. According to the concept, causality and time do not work in the conventional sense and remarkably, an effect can predate its cause, thus reversing the directionality of time as well.

Usually, in the classical world, this is not what we actually experience. For every cause, there is a corresponding effect, but they work sequentially rather than in the reverse way. Conventional thought process suggests that once a particular event has occurred, there’s almost zero probability that it can be reversed. The physical reason is simple, and it has to do with the arrow of time. In general, the arrow of time points in a single forward direction and this is one of the major unsolved challenges of the foundations of physics because physicists are uncertain of why the nature of time is such.

Researchers at the University of Bonn have demonstrated that super photons, or photon Bose-Einstein condensates, conform to fundamental physics theorems, enabling insights into properties that are often difficult to observe.

Under suitable conditions, thousands of particles of light can merge into a type of “super photon.” Physicists call such a state a photon Bose-Einstein condensate. Researchers at the University of Bonn have now shown that this exotic quantum state obeys a fundamental theorem of physics. This finding now allows one to measure properties of photon Bose-Einstein condensates which are usually difficult to access. The study was published on June 3 in the journal Nature Communications.

If many atoms are cooled to a very low temperature confined in a small volume, they can become indistinguishable and behave like a single “super particle.” Physicists also call this a Bose-Einstein condensate or quantum gas. Photons condense based on a similar principle and can be cooled using dye molecules. These molecules act like small refrigerators and swallow the “hot” light particles before spitting them out again at the right temperature.

Several branches of modern physics, including quantum theory and cosmology, suggest our universe may be just one of many.

By Sarah Scoles

Humans live in a universe; that is a fact. Up for debate, though, is whether that universe lives in a sea of other universes— a multiverse.

Some scientists speculate that the strange happenings in this microscopic realm may hold the key to understanding consciousness. But scant evidence has left the majority skeptical.

That includes Christof Koch, Ph.D., meritorious investigator at the Allen Institute. As he wrote in his recent book, Then I am myself the world, “the brain is wet and warm, hardly conducive to subtle quantum interactions.”

Continue reading “Quantum mechanics and the puzzle of human consciousness” »

A new study published in Nature Physics introduces a theory of electron-phonon coupling that is affected by the quantum geometry of the electronic wavefunctions.

The movement of electrons in a lattice and their interactions with the lattice vibrations (or phonons) play a pivotal role in phenomena like superconductivity (resistance-free conductivity).

Electron-phonon coupling (EPC) is the interaction between free electrons and phonons, which are quasiparticles representing the vibrations of a crystal lattice. EPC leads to the formation of Cooper pairs (pairs of electrons), responsible for superconductivity in certain materials.

Researchers at QuTech have found a way to make Majorana particles in a two-dimensional plane. This was achieved by creating devices that exploit the combined material properties of superconductors and semiconductors. The inherent flexibility of this new 2D platform should allow one to perform experiments with Majoranas that were previously inaccessible. The results are published in Nature.