What can we do with the amazing property of quantum entanglement?
The cutting edge field of physics known as quantum mechanics is the new “rocket science” for the 21st century. The study of the quantum has been a wellspring of new understanding as we work to understand the often weird behavior of the smallest particles of matter that make up the universe around us.
Computer scientists are currently working around the world to take advantage of this inherent quantum power to develop quantum computing technology. The scientific and business communities see vast possibilities for quantum computing (QC), but although entanglement is a proven concept there are still many pieces of the puzzle left to place. Dozens of large corporations as well as startups are involved in the quantum race, as well as every nation with the requisite expertise. The United States Air Force alone has already invested over $5 billion in quantum research.
Companies like the British Columbia-based D-Wave are already selling services that use quantum computers to complement classical computer systems. In D-Wave’s case, they actually sell a quantum computer model called the D-Wave 2000Q.
Rather than store information using bits represented by 0s or 1s as conventional digital computers do, quantum computers use quantum bits, or qubits, to encode information as 0s, 1s, or both at the same time. This superposition of states — along with the other quantum mechanical phenomena of entanglement and tunneling — enables quantum computers to manipulate enormous combinations of states at once.
Qubits can exhibit a property called quantum entanglement, in which 2 qubits are mysteriously linked, no matter how far apart they may be in the physical world, and react to one another’s states. Using this property, we can measure one qubit and be able to know the properties of its entangled qubit at the same time. Erwin Schrödinger discovered quantum entanglement in 1935, and worked to elucidate it further with Albert Einstein. Einstein famously termed entanglement “spooky action at a distance”.
Our plan is that by 2020, or maybe as soon as next year, to achieve ‘quantum supremacy’ with calculation power one million times to all existing computers around the world combined.
— Pan Jianwei, VP, University of Science & Technology of China
Quantum entanglement has also enabled research into what is called quantum teleportation. By taking previously-entangled particles and placing them in different locations, we can use traditional communication methods to send the states of one particle to the entangled partner no matter how far apart they might be.
Usually, once a measurement is made, the particles lose their entangled properties. However, this may not always be the case. Some researchers believe they can make quantum entanglement-based processes more efficient:
…one pair of entangled particles can be used again and again to “catalyze” certain “reactions” between other entangled pairs because it is returned unchanged. With such recycling, maneuvers in quantum computing or cryptography might require fewer entangled pairs in order to operate.
The first practical experiments using photons happened in 1998 at Caltech communicated the state of one photon across a meter distance to its entangled partner and successfully made a copy of the first. The scientists had to use 3 photons to achieve this: One that would be “teleported” [A], one to transport [B], and another that is entangled with the transporting photon [C]. In essence, C became A.
In 2012, we achieved a landmark feat when Chinese researchers were able to teleport the quantum states of the first “macroscopic” object — a group of 100 million rubidium atoms.
In 2017, Chinese scientists sent the information for the quantum state of one photon to an orbital satellite equipped 870 miles above Earth. This information was detected and then relayed to the photon’s entangled partner, which then became a “mirror copy” of its partner on Earth. The same research group then reversed this accomplishment and sent the entangled photon states from a satellite to two ground stations. These feats were the farthest distances that quantum teleportation has ever been demonstrated at.
It’s important to note that we are not sending actual data like we do with a fax machine in these experiments. What’s happening is that we are measuring the entangled particles’ states, which are correlated despite the distance between them. We don’t know what those states are until we observe them.
While the laws of physics so far do not allow for teleportation as seen in Star Trek or The Fly, there are numerous possible uses for quantum teleportation that will benefit us. One of the most amazing applications may allow us to build copies of ourselves in some far distant world.
Consider this: We would first scan a human and then create a “golem”-like assembly of atoms that contains all of the particles found in our human subject. Next, the “golem” and the original’s particles are entangled. The golem is sent to one of our nearest potentially habitable alien worlds, perhaps in Alpha Centauri, where for decades previous our terraforming technology has been hard at work. Finally, once our golem has arrived in the neighboring star system, we make our observation of the human subject on Earth and send that information across light years to the waiting raw materials. The golem receives the data and conforms to our observation of the subject, becoming an exact duplicate of the very distant Earthbound human.
Another amazing use for quantum teleportation, and not quite as far-fetched, is a quantum internet. This would let users communicate between quantum-entangled nodes on a network, allowing for the sending of unhackable information via quantum key distribution.
The reality is that we will probably see a fundamentally more powerful internet due to our quantum research over the next 10–20 years, and be able to take full advantage of quantum computing. This will help propel us into the future ever faster by enhancing our ability to generate massive numbers of simulations and optimizations. In the long run, as humanity branches out into other solar systems, quantum teleportation may be most useful for peer-to-peer communication in some kind of galactic network.
And, perhaps one day in the next century, we might be recreating a human consciousness on some distant world.
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