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A group of physicists wants to use artificial intelligence to prove that reality doesn’t exist. They want to do this by running an artificial general intelligence as an observer on a quantum computer. I wish this was a joke. But I’m afraid it’s not.

Paper here: https://quantum-journal.org/papers/q–…

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One of the greatest mysteries of science could be one step closer to being solved. Approximately 80% of the matter in the universe is dark, meaning that it cannot be seen. In fact, dark matter is passing through us constantly—possibly at a rate of trillions of particles per second.

We know it exists because we can see the effects of its gravity, but experiments to date have so far failed to detect it.

Taking advantage of the most advanced quantum technologies, scientists from Lancaster University, the University of Oxford, and Royal Holloway, University of London are building the most sensitive dark matter detectors to date.

Recent observations by ESA’s XMM-Newton and NASA ’s Chandra have revealed three unusually cold, young neutron stars, challenging current models by showing they cool much faster than expected.

This finding has significant implications, suggesting that only a few of the many proposed neutron star models are viable, and pointing to a potential breakthrough in linking the theories of general relativity and quantum mechanics through astrophysical observations.

Discovery of unusually cold neutron stars.

Researchers at the Paul-Drude-Institute for Solid State Electronics (PDI) have observed a novel modulation regime characterized by the emergence of previously unseen “acceleration beats” in a modulated semiconductor-based laser.

As they detail in a paper published today in Nature Communications, the key—and somewhat counterintuitive—feature of this novel regime is the ability to coherently manipulate quantum systems using modulation periods longer than the coherence time, provided that the modulation amplitude is large enough.

Harmonic modulation of light sources, such as lasers, is the cornerstone of many modern and emergent telecommunications technologies. In this regard, two regimes of modulation are well-known: the adiabatic regime and the non-adiabatic regime.

Scientists have made a significant breakthrough in creating a new method for transmitting quantum information using particles of light called qudits. These qudits promise a future quantum internet that is both secure and powerful. The study is published in the journal eLight.

Traditionally, quantum information is encoded on qubits, which can exist in a state of 0, 1, or both at the same time (superposition). This quality makes them ideal for complex calculations but limits the amount of data they can carry in communication. Conversely, qudits can encode information in higher dimensions, transmitting more data in a single go.

The new technique harnesses two properties of light—spatial mode and polarization—to create four-dimensional qudits. These qudits are built on a special chip that allows for precise manipulation. This manipulation translates to faster data transfer rates and increased resistance to errors compared to conventional methods.

Is nature really as strange as quantum theory says—or are there simpler explanations? Neutron measurements at TU Wien prove that it doesn’t work without the strange properties of quantum theory.

Can a particle be in two different places at the same time? In quantum physics, it can: Quantum theory allows objects to be in different states at the same time—or more precisely: in a superposition state, combining different observable states. But is this really the case? Perhaps the particle is actually in a very specific state, at a very specific location, but we just don’t know it?

The question of whether the behavior of quantum objects could perhaps be described by a simple, more classical theory has been discussed for decades. In 1985, a way of measuring this was proposed: the so-called “Leggett-Garg inequality.” Any theory that describes our world without the strange superposition states of quantum theory must obey this inequality.

In a single leap from tabletop to the microscale, engineers at Stanford University have produced the world’s first practical titanium-sapphire laser on a chip.

Researchers have developed a chip-scale Titanium-sapphire laser that is significantly smaller and less expensive than traditional models, making it accessible for broader applications in quantum optics, neuroscience, and other fields. This new technology is expected to enable labs to have hundreds of these powerful lasers on a single chip, fueled by a simple green laser pointer.

As lasers go, those made of Titanium-sapphire (Ti: sapphire) are considered to have “unmatched” performance. They are indispensable in many fields, including cutting-edge quantum optics, spectroscopy, and neuroscience. But that performance comes at a steep price. Ti: sapphire lasers are big, on the order of cubic feet in volume. They are expensive, costing hundreds of thousands of dollars each. And they require other high-powered lasers, themselves costing $30,000 each, to supply them with enough energy to function.

A recent study has unveiled the origins of the mysterious “heartbeats” observed in neutron stars, relating them to glitches caused by the dynamics of superfluid vortices.

Researchers found that these glitches follow a power-law distribution similar to other complex systems and developed a model based on quantum vortex networks that aligns with observed data without extra tuning.

Discovering Neutron Stars’ Heartbeats

A groundbreaking study has demonstrated the use of liquid crystals for efficient and tunable spontaneous parametric down-conversion (SPDC), expanding the potential of quantum light sources beyond traditional solid materials.

Spontaneous parametric down-conversion (SPDC), a key method for generating entangled photons used in quantum physics and technology, has traditionally been restricted to solid materials. However, researchers at the Max Planck Institute for the Science of Light (MPL) and the Jozef Stefan Institute in Ljubljana, Slovenia, have recently achieved a breakthrough by demonstrating SPDC in a liquid crystal for the first time. Their findings, published in Nature, pave the way for the development of a new generation of quantum sources that are both efficient and tunable by electric fields.

The splitting of a single photon in two is one of the most useful tools in quantum photonics. It can create entangled photon pairs, single photons, squeezed light, and even more complicated states of light which are essential for optical quantum technologies. This process is known as spontaneous parametric down-conversion (SPDC).

Recent research has advanced the development of electron-on-solid-neon qubits, revealing key insights that improve quantum computing by extending qubit coherence times and optimizing their design.

Quantum computers have the potential to be revolutionary tools for their ability to perform calculations that would take classical computers many years to resolve.

But to make an effective quantum computer, you need a reliable quantum bit, or qubit, that can exist in a simultaneous 0 or 1 state for a sufficiently long period, known as its coherence time.