In the journal of Proceedings of the National Academy of Sciences (PNAS), an article was published this week by a team of Spanish scientists that suggests how quantum entanglement of subatomic particles could be used to create supercomputers with better encryption and higher processing speeds. In a news release by the Universitat Autonoma de Barcelona, researchers detailed how they had achieved 103 dimensions through the entanglement of only two particles.
The states that photons can achieve seems to be illogical, especially with the occurrence of superposition, an overlap in which particles can exhibit more than one state at any given time, and the existence of quantum entanglement by which an elementary particle can be at two places at once. In science this will greatly advance the study of quantum mechanics, and in the realm of computers it makes the function of multiple processes lightning fast.
Research was led by Mario Krenn and Anton Zeilinger, from the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, and included Marcus Huber, from the Group of Quantum Information and Quantum Phenomena from the UAB Department of Physics. Before now, scientists have looked into increasing the capacity of computers by using a greater number of entangled particles in a two-dimensional state called a qubit. This superposition of information allows values that constitute the digital expression of not only a one or a zero, but an overlap that makes it simultaneously both. With this method, researchers were capable of entangling 14 particles.
After years of combining the properties of superposition in a single network that uses entanglement to affect different parts of the system immediately, scientists modified their approach so that instead of using one qubit for many entangled particles, they created a single pair of entangled photons that could exist in more than one hundred states at once. These variations reflect different modes relative to angular momentum, as well as the intensity and characteristic of each phase.
In quantum mechanics, entanglement is a phenomenon by which multiple particles interact in such a way as to cease to be individuals and the same state can be classified for both. The correlation of measurements can then be applied, from position to polarity, with such reliance as to be able to foretell the spin of a particle upon its axis based upon the movement of what it is entangled with.
Superposition is a system of understanding that expands in non-linear directions from Schrodinger’s calculations, which constitute a differential equation that describes how quantum states change over time based upon a linear concept of investigation. This new way of perceiving multiple states existing at once and independent of external investigation is detailed from scientific weaknesses highlighted by the Heisenberg uncertainty principle, which posits how the limitations of mathematical precision can only discover the position or momentum, but not both simultaneously, of subatomic particles based upon the equations used.
Since humans are incapable of seeing the minuscule world directly, scientists are forced to rely upon observations derived from individual measurements designed to view specific variables, thereby leaving the unseen variable a complete mystery. Using a model designed by Alan Turing in the 1930s, modern computers use bits of information to communicate with itself through a binary code in which this information can only be active or inactive, either functioning or not at any given time. Qubits, however, can exist in a mixed state between active and inactive, and therefore while the Turing model is capable of making one linear calculation at a time, quantum supercomputers will be multi-tasking in a non-linear way that allows for exponentially faster performance.
In the research conducted by Zeilinger and Krenn, their conclusion was that the next step involved learning how to control the 103 spatial modes of photons for the purpose of manipulating and designing new computer hardware. By using quantum entanglement with the development of supercomputers, these alternative states can coexist without measurement and will therefore exhibit both states at once, allowing for digital expansion beyond the realm of the known.
By Elijah Stephens