Quantum entanglement realized between distant large objects

Light propagates through the atomic cloud shown in the center and then falls onto the SiN membrane shown on the left. As a result of interaction with light the precession of atomic spins and vibration of the membrane become quantum correlated. This is the essence of entanglement between the atoms and the membrane. Credit: Niels Bohr Institute

A team of researchers from the University of Copenhagen’s Niels Bohr Institute has successfully entangled two very distinct quantum particles. The findings, which were reported in Nature Physics, have various possible applications in ultra-precise sensing and quantum communication.

Quantum communication and quantum sensing are both based on entanglement. It’s a quantum link between two items that allows them to act as if they’re one quantum object.

Researchers were able to create entanglement between a mechanical oscillator—a vibrating dielectric membrane—and a cloud of atoms, each serving as a small magnet, or «spin,» according to physicists. By joining these disparate entities with photons, or light particles, they were able to entangle. The membrane—or mechanical quantum systems in general—can be used to process quantum information, and the membrane—or mechanical quantum systems in general—can be used to store quantum information.

Professor Eugene Polzik, the project’s leader, says: «We’re on our way to pushing the boundaries of entanglement’s capabilities with this new technique. The larger the objects, the further away they are, and the more different they are, the more intriguing entanglement becomes from both a basic and an applied standpoint. Entanglement between highly diverse things is now conceivable thanks to the new result.»

Imagine the position of the vibrating membrane and the tilt of the total spin of all atoms, similar to a spinning top, to explain entanglement using the example of spins entangled with a mechanical membrane. A correlation occurs when both items move randomly yet are observed travelling right or left at the same moment. The so-called zero-point motion—the residual, uncorrelated motion of all matter that occurs even at absolute zero temperature—is generally the limit of such correlated motion. This limits our understanding of any of the systems.

Eugene Polzik’s team entangled the systems in their experiment, which means they moved in a correlated way with more precision than zero-point motion. «Quantum mechanics is a double-edged sword—it gives us amazing new technology, but it also restricts the precision of measurements that would appear simple from a classical standpoint,» explains Micha Parniak, a team member. Even if they are separated by a large distance, entangled systems can maintain perfect correlation, a fact that has perplexed academics since quantum physics’ inception more than a century ago.

Christoffer stfeldt, a Ph.D. student, elaborates: «Consider the many methods for manifesting quantum states as a zoo of diverse realities or circumstances, each with its own set of features and potentials. If, for example, we want to construct a gadget that can take advantage of the many attributes they all have and perform different functions and accomplish different tasks, we’ll need to invent a language that they can all understand. For us to fully utilise the device’s capabilities, the quantum states must be able to communicate. This entanglement of two zoo elements has demonstrated what we are presently capable of.»

Quantum sensing is an example of distinct perspectives on entangling different quantum things. Different objects have different levels of sensitivity to external pressures. Mechanical oscillators, for example, are employed in accelerometers and force sensors, while atomic spins are used in magnetometers. Entanglement permits only one of the two entangled objects to be measured with a sensitivity not restricted by the object’s zero-point fluctuations when only one of the two is subject to external perturbation.

The approach has the potential to be used in sensing for both small and large oscillators in the near future. The first detection of gravity waves, performed by the Laser Interferometer Gravitational-wave Observatory, was one of the most significant scientific breakthroughs in recent years (LIGO). LIGO detects and monitors extremely faint waves produced by deep-space astronomical events such as black hole mergers and neutron star mergers. The waves can be seen because they shake the interferometer’s mirrors. However, quantum physics limits LIGO’s sensitivity since the laser interferometer’s mirrors are likewise disturbed by zero-point fluctuations. These variations produce noise, which makes it impossible to see the tiny movements of the mirrors induced by gravitational waves.

It is theoretically possible to entangle the LIGO mirrors with an atomic cloud and so cancel the reflectors’ zero-point noise in the same manner that the membrane noise is cancelled in the current experiment. Due to their entanglement, the mirrors and atomic spins have a perfect correlation that can be used in such sensors to almost eliminate uncertainty. It’s as simple as taking data from one system and applying what you’ve learned to the other. In this method, one may simultaneously learn about the position and momentum of LIGO’s mirrors, entering a so-called quantum-mechanics-free subspace and moving closer to unlimited precision in motion measurements. A model experiment demonstrating this principle is on the way at Eugene Polzik’s laboratory.

Link original: https://www.sciandnature.com/2022/01/quantum-entanglement-realized-between.html?fbclid=IwAR2RyzFbzEcknG2KeoBoJo7TY4wzVHpjKqFRjbI57OxqMVexRiObG-wwh8c


Some Scientists Believe the Universe Is Conscious

In upcoming research, scientists will attempt to show the universe has consciousness. Yes, really. No matter the outcome, we’ll soon learn more about what it means to be conscious—and which objects around us might have a mind of their own.

What will that mean for how we treat objects and the world around us? Buckle in, because things are about to get weird.

What Is Consciousness?

The basic definition of consciousness intentionally leaves a lot of questions unanswered. It’s “the normal mental condition of the waking state of humans, characterized by the experience of perceptions, thoughts, feelings, awareness of the external world, and often in humans (but not necessarily in other animals) self-awareness,” according to the Oxford Dictionary of Psychology.

Scientists simply don’t have one unified theory of what consciousness is. We also don’t know where it comes from, or what it’s made of.

However, one loophole of this knowledge gap is that we can’t exhaustively say other organisms, and even inanimate objects, don’t have consciousness. Humans relate to animals and can imagine, say, dogs and cats have some amount of consciousness because we see their facial expressions and how they appear to make decisions. But just because we don’t “relate to” rocks, the ocean, or the night sky, that isn’t the same as proving those things don’t have consciousness.

This is where a philosophical stance called panpsychism comes into play, writes All About Space’s David Crookes:

“This claims consciousness is inherent in even the tiniest pieces of matter — an idea that suggests the fundamental building blocks of reality have conscious experience. Crucially, it implies consciousness could be found throughout the universe.”

It’s also where physics enters the picture. Some scientists have posited that the thing we think of as consciousness is made of micro-scale quantum physics events and other “spooky actions at a distance,” somehow fluttering inside our brains and generating conscious thoughts.

The Free Will Conundrum

One of the leading minds in physics, 2020 Nobel laureate and black hole pioneer Roger Penrose, has written extensively about quantum mechanics as a suspected vehicle of consciousness. In 1989, he wrote a book called The Emperor’s New Mind, in which he claimed “that human consciousness is non-algorithmic and a product of quantum effects.”

Let’s quickly break down that statement. What does it mean for human consciousness to be “algorithmic”? Well, an algorithm is simply a series of predictable steps to reach an outcome, and in the study of philosophy, this idea plays a big part in questions about free will versus determinism.

Are our brains simply cranking out math-like processes that can be telescoped in advance? Or is something wild happening that allows us true free will, meaning the ability to make meaningfully different decisions that affect our lives?

Within philosophy itself, the study of free will dates back at least centuries. But the overlap with physics is much newer. And what Penrose claimed in The Emperor’s New Mind is that consciousness isn’t strictly causal because, on the tiniest level, it’s a product of unpredictable quantum phenomena that don’t conform to classical physics.

So, where does all that background information leave us? If you’re scratching your head or having some uncomfortable thoughts, you’re not alone. But these questions are essential to people who study philosophy and science, because the answers could change how we understand the entire universe around us. Whether or not humans do or don’t have free will has huge moral implications, for example. How do you punish criminals who could never have done differently?

Consciousness Is Everywhere

In physics, scientists could learn key things from a study of consciousness as a quantum effect. This is where we rejoin today’s researchers: Johannes Kleiner, mathematician and theoretical physicist at the Munich Center For Mathematical Philosophy, and Sean Tull, mathematician at the University of Oxford.

Kleiner and Tull are following Penrose’s example, in both his 1989 book and a 2014 paper where he detailed his belief that our brains’ microprocesses can be used to model things about the whole universe. The resulting theory is called integrated information theory (IIT), and it’s an abstract, “highly mathematical” form of the philosophy we’ve been reviewing.

In IIT, consciousness is everywhere, but it accumulates in places where it’s needed to help glue together different related systems. This means the human body is jam-packed with a ton of systems that must interrelate, so there’s a lot of consciousness (or phi, as the quantity is known in IIT) that can be calculated. Think about all the parts of the brain that work together to, for example, form a picture and sense memory of an apple in your mind’s eye.

The revolutionary thing in IIT isn’t related to the human brain—it’s that consciousness isn’t biological at all, but rather is simply this value, phi, that can be calculated if you know a lot about the complexity of what you’re studying.

If your brain has almost countless interrelated systems, then the entire universe must have virtually infinite ones. And if that’s where consciousness accumulates, then the universe must have a lot of phi.

Hey, we told you this was going to get weird.

“The theory consists of a very complicated algorithm that, when applied to a detailed mathematical description of a physical system, provides information about whether the system is conscious or not, and what it is conscious of,” Kleiner told All About Space. “If there is an isolated pair of particles floating around somewhere in space, they will have some rudimentary form of consciousness if they interact in the correct way.”

Kleiner and Tull are working on turning IIT into this complex mathematical algorithm—setting down the standard that can then be used to examine how conscious things operate. 

Think about the classic philosophical comment, “I think, therefore I am,” then imagine two geniuses turning that into a workable formula where you substitute in a hundred different number values and end up with your specific “I am” answer.

The next step is to actually crunch the numbers, and then to grapple with the moral implications of a hypothetically conscious universe. It’s an exciting time to be a philosopher—or a philosopher’s calculator.

Link Original: https://www.popularmechanics.com/science/a36329671/is-the-universe-conscious/?utm_source=facebook&utm_medium=social-media&utm_campaign=socialflowFBPOP&fbclid=IwAR2RtikR_vKNp0wepXtQ_QEq1o438qMPsGLEB5RV4czuo6M7lcRgWO-c1hI