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.
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.
Conventional encryption methods rely on complex mathematical algorithms and the limits of current computing power. However, with the rise of quantum computers, these methods are becoming increasingly vulnerable, necessitating quantum key distribution (QKD).
QKD is a technology that leverages the unique properties of quantum physics to secure data transmission. This method has been continuously optimized over the years, but establishing large networks has been challenging due to the limitations of existing quantum light sources.
In a new article published in Light: Science & Applications, a team of scientists in Germany have achieved the first intercity QKD experiment with a deterministic single-photon source, revolutionizing how we protect our confidential information from cyber threats.
Accurate models of real-world scenarios are important for bringing theoretical and experimental research together in meaningful ways. Creating these realistic computer models, however, is a very large undertaking. Significant amounts of data, code, and expertise across a wide range of intricate areas are needed to create useful and comprehensive software.
Dr. Norbert Lütkenhaus, executive director of the Institute for Quantum Computing (IQC) and a professor in the University of Waterloo’s Department of Physics and Astronomy, alongside his research group, have spent the last several years developing accurate software models for research in quantum key distribution (QKD).
QKD is a process for cryptography that harnesses fundamental principles of quantum mechanics to exchange secret keys, which can then be used to ensure secure communication.
#aliens #robots Welcome to an extraordinary exploration of artificial intelligence and its cosmic counterpart, the astro-chicken! Join me in this mind-blowing video where we delve into the captivating concept of interstellar colonization. You can find my book Gravity: From Falling Apples to Supermassive Black Holes here on Amazon: https://www.amazon.co.uk/Gravity-Fall… The Cosmic Mystery Tour here: https://www.amazon.co.uk/Cosmic-Myste… Artificial intelligences offers the only way to explore the stars. Humans are very delicate and not at all suited to interstellar travel. After all, it is a long long way to the stars. The nearest star is 40 trillion kilometres away. The distance between the stars is too great for it to be feasible to travel so far within human lifespans. The limitations of our biology will prevent us from exploring deep space in person. Although we might like to fantasize about traveling from star system to star system with Captain Kirk, it is almost inconceivable that any humans will ever reach the stars. But maybe there is another way to colonize the galaxy. The British theoretical physicist Freeman Dyson certainly thought so. In the 1960s Dyson, who was one of the architects of quantum electrodynamics — our best theory of electromagnetism — speculated that any sufficiently advanced civilisation would explore the galaxy by launching fleets of autonomous self-replicating robots. There are, of course, many advantages to sending robots rather than humanoids. Robots are more robust than organic lifeforms, they never get bored, and they require far less in the way of maintenance and life support systems. They can survive in harsh environments, and they are adaptable — they can be upgraded. Robots equipped with artificial intelligence could operate autonomously and perform tasks that are impossible for humans, and they could survive indefinitely. Robots could also be miniaturized so they would require far less propulsion to send them on their way. Dyson’s robots would take a blueprint or template that would enable them to create more self-replicating robots. On arrival at a suitable asteroid or planet they would establish a base and set up a means of generating and storing energy. They would then extract and refine minerals and eventually build factories with assembly lines for creating more autonomous robots, each with its own copy of the blueprint, and a propulsion system for the colonization of other star systems. Dyson called these robots astro-chickens. They would travel between the stars as cosmic eggs, hatch on arrival at a suitable destination, then create and disperse the next generation of cosmic eggs. There is no reason, in principle, why super-advanced civilizations could not create such robot explorers. They could attain high speeds as cosmic eggs using some sort of nuclear fusion engine, perhaps. The diameter of our galaxy is about 100,000 light years. Traveling between stars at a significant fraction of the speed of light, the astro-chickens could colonize the entire galaxy in under one million years, which is not long by astronomical or evolutionary time-scales. So where are the astro-chickens? No artefact of an alien civilization has ever been discovered. But, if alien civilizations exist, it might be easier to find their robot descendants than the original aliens. Maybe they are closer than we think. In fact, I have already created my own design for an autonomous, self-replicating robot, which you can witness here on my laptop. Prepare to be enthralled!
A research team led by Director Jo Moon-Ho of the Center for Van der Waals Quantum Solids within the Institute for Basic Science (IBS) has implemented a novel method to achieve epitaxial growth of 1D metallic materials with a width of less than 1 nm. The group applied this process to develop a new structure for 2D semiconductor logic circuits. Notably, they used the 1D metals as a gate electrode of the ultra-miniaturized transistor.
This research appears in Nature Nanotechnology.
Integrated devices based on two-dimensional (2D) semiconductors, which exhibit excellent properties even at the ultimate limit of material thickness down to the atomic scale, are a major focus of basic and applied research worldwide. However, realizing such ultra-miniaturized transistor devices that can control the electron movement within a few nanometers, let alone developing the manufacturing process for these integrated circuits, has been met with significant technical challenges.
