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Using drones to create local quantum networks

A team of researchers affiliated with several institutions in China has used drones to create a prototype of a small airborne quantum network. In their paper published in the journal Physical Review Letters, the researchers describe sending entangled particles from one drone to another and from a drone to the ground.

Computer scientists, physicists and engineers have been working over the last several years toward building a usable quantum —doing so would involve sending entangled particles between users and the result would be the most secure network ever made. As part of that effort, researchers have sent entangled particles over fiber cables, between towers and even from satellites to the ground. In this new effort, the researchers have added a new element—drones.

To build a long-range quantum network, satellites appear to be the ideal solution. But for smaller networks, such as for communications between users in the same city, another option is needed. While towers can be of some use, they are subject to weather and blockage, intentional or otherwise. To get around this problem, the researchers used drones to carry the signals.

Scientists’ discovery is paving the way for novel ultrafast quantum computers

Scientists at the Institute of Physics of the University of Tartu have found a way to develop optical quantum computers of a new type. Central to the discovery are rare earth ions that have certain characteristics and can act as quantum bits. These would give quantum computers ultrafast computation speed and better reliability compared to earlier solutions. The University of Tartu researchers Vladimir Hizhnyakov, Vadim Boltrushko, Helle Kaasik and Yurii Orlovskii published the results of their research in the scientific journal Optics Communications.

While in ordinary computers, the units of information are binary digits or bits, in quantum computers the units are quantum bits or qubits. In an ordinary , information is mostly carried by electricity in memory storage cells consisting of field-effect transistors, but in a quantum computer, depending on the type of computer, the information carriers are much smaller particles, for example ions, photons and electrons. The information may be carried by a certain characteristic of this particle (for example, spin of electron or polarization of photon), which may have two states. While the values of an ordinary bit are 0 or 1, also intermediate variants of these values are possible in the quantum bit. The intermediate state is called the superposition. This property gives quantum computers the ability to solve tasks, which ordinary computers are unable to perform within reasonable time.

Human Mind Control of Rat Cyborg’s Continuous Locomotion with Wireless Brain-to-Brain Interface

“The results showed that rat cyborgs could be smoothly and successfully navigated by the human mind to complete a navigation task in a complex maze. Our experiments indicated that the cooperation through transmitting multidimensional information between two brains by computer-assisted BBI is promising.”

(2019)


Brain-machine interfaces (BMIs) provide a promising information channel between the biological brain and external devices and are applied in building brain-to-device control. Prior studies have explored the feasibility of establishing a brain-brain interface (BBI) across various brains via the combination of BMIs. However, using BBI to realize the efficient multidegree control of a living creature, such as a rat, to complete a navigation task in a complex environment has yet to be shown. In this study, we developed a BBI from the human brain to a rat implanted with microelectrodes (i.e., rat cyborg), which integrated electroencephalogram-based motor imagery and brain stimulation to realize human mind control of the rat’s continuous locomotion. Control instructions were transferred from continuous motor imagery decoding results with the proposed control models and were wirelessly sent to the rat cyborg through brain micro-electrical stimulation. The results showed that rat cyborgs could be smoothly and successfully navigated by the human mind to complete a navigation task in a complex maze. Our experiments indicated that the cooperation through transmitting multidimensional information between two brains by computer-assisted BBI is promising.

The incredible physics behind quantum computing | Brian Greene, Michio Kaku, & more | Big Think

The incredible physics behind quantum computing.
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While today’s computers—referred to as classical computers—continue to become more and more powerful, there is a ceiling to their advancement due to the physical limits of the materials used to make them. Quantum computing allows physicists and researchers to exponentially increase computation power, harnessing potential parallel realities to do so.

Quantum computer chips are astoundingly small, about the size of a fingernail. Scientists have to not only build the computer itself but also the ultra-protected environment in which they operate. Total isolation is required to eliminate vibrations and other external influences on synchronized atoms; if the atoms become ‘decoherent’ the quantum computer cannot function.

“You need to create a very quiet, clean, cold environment for these chips to work in,” says quantum computing expert Vern Brownell. The coldest temperature possible in physics is-273.15 degrees C. The rooms required for quantum computing are-273.14 degrees C, which is 150 times colder than outer space. It is complex and mind-boggling work, but the potential for computation that harnesses the power of parallel universes is worth the chase.

Check Chris Bernhardt’s book “Quantum Computing for Everyone (MIT Press)” at http://amzn.to/3nSg5a8
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TRANSCRIPT:

MICHIO KAKU: Years ago, we physicists predicted the end of Moore’s Law, which says a computer power doubles every 18 months. But we also, on the other hand, proposed a positive program—perhaps molecular computers, quantum computers can take over when silicon power is exhausted. In fact, already we see a slowing down of Moore’s Law. Computer power simply cannot maintain its rapid exponential rise using standard silicon technology. The two basic problems are heat and leakage. That’s the reason why the age of silicon will eventually come to a close. No one knows when, but as I mentioned we already now can see the slowing down of Moore’s Law, and in 10 years it could flatten out completely. So what’s the problem? The problem is that a Pentium chip today has a layer almost down to 20 atoms across, 20 atoms across. When that layer gets down to about five atoms across, it’s all over. You have two effects, heat. The heat generated will be so intense that the chip will melt. You can literally fry an egg on top of the chip, and the chip itself begins to disintegrate. And second of all, leakage. You don’t know where the electron is anymore. The quantum theory takes over. The Heisenberg Uncertainty Principle says you don’t know where that electron is anymore, meaning it could be outside the wire, outside the Pentium chip or inside the Pentium chip. So there is an ultimate limit set by the laws of thermodynamics and set by the laws of quantum mechanics, as to how much computing power you can do with silicon.

VERN BROWNELL: I refer to today’s computers as classical computers. They compute largely in the same way they have for the past 60 or 70 years, since John Von Neumann and others invented the first electronic computers back in the ‘40s. And we’ve had amazing progress over those years. Think of all the developments there’ve been on the hardware side and the software side over those 60 or 70 years and how much energy and development has been put into those areas. And we’ve achieved marvelous things with that classical computing environment, but it has its limits too, and people sometimes ask, “Why would we need any more powerful computers?” These applications, these problems that we’re trying to solve, are incredibly hard problems and aren’t well-suited for the architecture of classical computing. So I see quantum computing as another set of tools, another set of resources for scientists, researchers, computer scientists, programmers, to develop and enhance some of these capabilities to really change the world in a much better way than we’re able to today with classical computers.

Quantum Drones Take Flight

A small prototype of a drone-based quantum network has successfully relayed a quantum signal over a kilometer of free space.

The airwaves are chock full of “classical” information from cell phones, radio stations, and Wi-Fi hubs, but one day those waves could be carrying quantum encrypted messages or data input for a quantum computer. A new experiment has used a pair of hovering drones to dole out quantum information to two ground stations separated by 1 km [1]. This demonstration could lead to a drone-based quantum network that could be positioned—and easily repositioned—over a city or rural area.

Quantum communication promises fully secure message sharing. For example, two users could exchange encrypted messages using “entangled” photons, pairs of particles with a unique quantum-mechanical relationship. For every pair, one photon would be sent to each of the users, who would be alerted to any eavesdropping by a loss of entanglement between the photons. One of the most common methods for sending such quantum encrypted messages relies on optical fibers (see Viewpoint: Record Distance for Quantum Cryptography). But in fibers, a large fraction of the photons scatter before reaching their destination. More photons can survive if quantum information is transmitted through the atmosphere, as in the quantum link established using a Chinese satellite in 2018 (see Focus: Intercontinental, Quantum-Encrypted Messaging and Video). However, satellites are expensive and difficult to adapt to changing demands on the ground.

Important Milestone in the Creation of a Quantum Computer That Uses Transistors As Qubits

One of the obstacles for progress in the quest for a working quantum computer has been that the working devices that go into a quantum computer and perform the actual calculations, the qubits, have hitherto been made by universities and in small numbers. But in recent years, a pan-European collaboration, in partnership with French microelectronics leader CEA-Leti, has been exploring everyday transistors — that are present in billions in all our mobile phones — for their use as qubits.

The French company Leti makes giant wafers full of devices, and, after measuring, researchers at the Niels Bohr Institute, University of Copenhagen, have found these industrially produced devices to be suitable as a qubit platform capable of moving to the second dimension, a significant step for a working quantum computer. The result is now published in Nature Communications.

One of the key features of the devices is the two-dimensional array of quantum dot. Or more precisely, a two by two lattice of quantum dots. “What we have shown is that we can realize single electron control in every single one of these quantum dots. This is very important for the development of a qubit, because one of the possible ways of making qubits is to use the spin of a single electron. So reaching this goal of controlling the single electrons and doing it in a 2D array of quantum dots was very important for us,” says Fabio Ansaloni, former PhD student, now postdoc at center for Quantum Devices, NBI.

Using electricity to increase the amount of data that can be stored

A team of researchers at Columbia University has developed a way to allow DNA strands to store more data. In their study, published in the journal Science, the group applied a small amount of electricity to DNA strands to allow for encoding more information than was possible with other methods.

For several years, researchers have been looking for ways to increase data storage capacity—storage requirements are expected to exceed capacity in the near future as demand skyrockets. One such approach has involved encoding data into strands of DNA—prior research has shown that it is possible. In the early stages of such research, scientists manually edited strands to add characteristics to represent zeroes or ones. More recently, researchers have used the CRISPR gene editing tool. Most such studies used DNA extracted from the tissue of deceased animals. More recently, researchers have begun efforts to move the research to living animals because it will last longer. And not just in the edited strands—the information they contain could conceivably be passed on to offspring, allowing data to be stored for very long periods of time.

Back in 2017, another team at Columbia University used CRISPR to detect a certain signal—in their case, it was the presence of sugar molecules. Adding such molecules resulted in gene expressions of plasmid DNA. Over time, the editing process was improved as genetic bits were added to represent ones and zeroes. Unfortunately, the system only allowed for storing a few bits of data.