Imagine a world where information can be transmitted securely across the globe, free from the prying eyes of hackers. Its incredible power lies in the realm of quantum mechanics, making it a groundbreaking advancement with immense potential for the future of telecommunications. There have been obstacles to conquer, but there has also been notable progress, exemplified by a recent achievement from researchers at Harvard University.

Using the existing fiber optics within the city of Boston, the team successfully demonstrated the longest transmission between two nodes. The fiber path covered a total distance of 35 kilometers (22 miles), encircling the entire city. The two nodes that connected to the close path were situated on different floors, making the fiber route not the shortest but rather an intriguing one.

Quantum information has been successfully transmitted over longer distances, showcasing remarkable advancements in this experiment that bring us closer to the realization of a practical quantum internet. The real breakthrough lies in the nodes, going beyond the mere utilization of optical fibers.

A typical network utilizes signal repeaters made of optical fiber. These devices incorporate optical receivers, electrical amplifiers, and optical transmitters. The signal is received, transformed into an electrical form, and subsequently converted back into light before being transmitted. They play a crucial role in expanding the reach of the original signal. And in its present state, this is not suitable for quantum internet.

The issue lies not in the technology, but rather in the fundamental principles of physics. Copying quantum information is not possible in that manner. Quantum information is highly secure due to its entangled state. The Harvard system operates by utilizing individual nodes that function as miniature quantum computers, responsible for storing, processing, and transferring information. This quantum network, consisting of only two nodes, is currently the most extensive one ever achieved, with nodes capable of such remarkable functionality.

“Demonstrating the ability to entangle quantum network nodes in a bustling urban environment is a significant milestone in enabling practical networking between quantum computers,” stated Professor Mikhail Lukin, the senior author.

At each node, a tiny quantum computer is constructed using a small piece of diamond that contains a flaw in its atomic arrangement known as a silicon vacancy center. At temperatures close to absolute zero, the silicon vacancy has the remarkable ability to capture, retain, and interconnect pieces of data, making it an ideal choice for a node.

“Given the existing entanglement between the light and the first node, it has the capability to transmit this entanglement to the second node,” elucidated Can Knaut, a graduate researcher in Lukin’s lab. “This phenomenon is known as photon-mediated entanglement.”

The study has been published in the prestigious journal Nature.

If you have accessed the Internet, it is likely that you are familiar with the Slow Mo Guys, who are YouTubers committed to capturing various events in slow motion. Their videos range from showcasing bullets colliding with each other to featuring Will Smith handling a large flamethrower in slow motion.

After engaging in the activity for more than ten years, the team pondered the possibility of endeavoring to capture on film “the swiftest phenomenon within the realm of human knowledge.” Light travels at the maximum speed allowed in the universe, which is 300,000 kilometers per second (186,000 miles per second).

In order to accomplish this task, they would require specialized apparatus, which they discovered at CalTech.

“We have recorded footage at extremely high frame rates.” “We are discussing a substantial amount, reaching up to approximately 500,000, which should not be underestimated,” clarifies the host in the video. “Their camera surpasses ours in quality and is capable of capturing 10 trillion frames per second.” Just for comparison, that is 20 million times quicker than the highest speed we have ever recorded on this channel.

They received assurance that they would be able to observe the speed of light thanks to the high frame rate from postdoctoral researcher Peng Wang from the Compressed Ultrafast Photography department. More precisely, they would observe the movement of light along the entire length of a bottle within a 2,000-picosecond duration of footage.

The team explains that the camera only sees light and that the bottle is added on top of that. Still, the result is amazing: 10 trillion frames per second of light being captured as it moves.

A novel approach to diamond production eliminates the need for extreme temperatures and pressures, thus making it possible to create diamonds at a significantly reduced cost. The world of precise crystal manipulation, as depicted in the science fiction novel The Diamond Age, may be within reach sooner than anticipated.

Despite our knowledge of synthetic diamond production dating back to the 1950s, the prevailing method still involves subjecting materials to extreme temperatures of 1,300–1,600 °C (2,400–2,900 °F) and applying 50,000 atmospheres of pressure for a period of 5–12 days. This has been instrumental in meeting the industrial demand for diamonds as cutting instruments while also offering unique colors for those with a preference for rare hues. Nevertheless, the expense of the procedure is comparable to that of discovering natural diamonds, whether for industrial use or as high-quality gemstones, which allows the mining industry to persist.

There might be a significant shift on the horizon as a method to produce diamonds under normal atmospheric pressure has been unveiled. The temperatures remain high at 1,025 °C (1,877 °F), but even at this level, significant savings can be achieved compared to the current heat requirements.

Low-pressure diamonds were once considered a paradoxical concept. Natural diamonds form deep within the Earth’s mantle under immense pressure from layers of crust above, and many of them were created long before complex life forms existed. The synthetic version utilizes liquid metal catalysts, but high pressures in the gigapascal range are still deemed necessary.

Nevertheless, scientists at Korea’s Institute for Basic Science have challenged this notion by demonstrating that diamonds can be grown using a liquid metal alloy of gallium, iron, nickel, and silicon, even without applying significant pressure in a hydrogen/methane atmosphere. The carbon in the diamond is derived from methane.

“This groundbreaking achievement was made possible through human creativity, persistent dedication, and the collaborative efforts of numerous contributors,” Professor Rod Ruoff stated. He omitted a significant amount of trial and error, which the team at the Institute employed while fine-tuning the combination of metals and other variables. When the team switched to a smaller chamber, they were able to make real progress in a surprisingly short amount of time, even though making the diamond itself was a quick process.

After extensive research, it was discovered that the diamonds tend to form at the lower part of the liquid alloy consisting of 77.75 percent gallium, 0.25 percent silicon, and 11 percent each of iron and nickel. It’s not a ratio that comes to mind right away. In addition, seed particles are not necessary for the production of these synthetic diamonds, unlike traditional methods.

“One day, when I conducted the experiment, subsequently cooled the graphite crucible to solidify the liquid metal, and extracted the solidified piece, I observed a fascinating pattern resembling a rainbow that extended over a few millimeters on the bottom surface of this piece,” shared graduate student Yan Gong. “We discovered that the colors of the rainbow are caused by diamonds!”

The process typically takes around 10 to 15 minutes to initiate diamond formation, with growth ceasing after approximately 150 minutes. However, the team is actively exploring methods to address this limitation.

The diamonds produced thus far are of a smaller size, resembling a film rather than a precious gemstone. As a result, diamond companies do not need to be overly concerned at this point. That could potentially change if scientists discover ways to enhance the supersaturated carbon layer that comes before the formation of diamonds. The silicon vacancy, which is highly sought after for creating colored diamonds, can also be created by nitrogen impurities. This characteristic makes these diamonds perfect for conducting experiments in the field of quantum computing.

The exact reasons behind the desired outcome of this particular combination of metals and gases remain a subject of ongoing investigation. The resemblance between silicon and carbon bonds is believed to play a crucial role. It is possible that carbon clusters containing silicon atoms could act as precursors to diamonds.

Mass production rarely relies on the initial iteration of a process demonstrated in a laboratory. According to Ruoff, there are several lower melting point metals that could be beneficial in terms of cost reduction or in creating diamonds with specific shades or properties.

The study has been published in the prestigious journal Nature.