When light is manipulated in a laboratory, it can create beautiful patterns that are just as unique and picturesque as a snowflake. These patterns aren’t just for show though; they serve an important purpose.
As Northrop Grumman’s Matthew O’Donnell explained, when you combine two or more vortices of light, they create petal patterns, which can create an “alphabet” for transmitting information — even quantum information — over large distances.
“If we ignore the fact that light is made up of discrete particles called photons and treat light as electromagnetic waves, then planar light consists of electromagnetic waves that are wiggling together in synchrony as the light propagates forward, much like a marching band in a parade moves together in lock-step along a boulevard,” O’Donnell said. “Vortices are different than plane waves in that the waves that make up the vortex are out of phase with respect to each other in just the right way so that the light propagates in a kind of tornado,” he added.
When you combine two or more petal patterns, they form interference patterns. These patterns consist of millions and millions of photons, said O’Donnell. If you have entangled photons or entangled optical vortices, that “opens up a new world of quantum communication, quantum encryption and quantum computing,” he noted.
How does this work? According to O’Donnell: “The idea of both these technologies is to leverage a resource known as entanglement only available by working at the discrete level of nature described by quantum theory. The quantum resource of entanglement allows technology to surpass limits normally constraining it from reaching a higher level of performance. Only quantum technology can operate at the absolute physical limit allowed by nature.”
For instance, take quantum computing. A quantum computer with fewer than 100 qubits — quantum bits — is known in many cases to outperform even the most powerful mainframe computers. A conventional computer performs calculations by performing operations on bits that can take on the value of either one or zero, nothing in between. (Bits are the fundamental units of computation, similar to how the whole numbers are manipulated to perform arithmetic.)
A quantum computer, on the other hand, performs calculations by operating on qubits which may take on the value of zero, one, or both at the same time. The latter situation is called being in a superposition of one and zero — something that can only happen in quantum.
Furthermore, unlike bits, qubits can be “entangled” with each other (another feature that is unique to quantum) to form a powerful computational network that can outperform any size of networked conventional computer cores. Now, petal patterns can be used as quantum bits. But, instead of being limited to superpositions of one and zero, petal patterns can be created as superpositions of tens or hundreds of different states. Imagine the complex networks that can be formed by entangling petal patterns with each other.
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