Entangled Quantum Particle Couple can be in 103 States, Study Shows

Researchers have now achieved a record quantum entanglement of 103 dimensions using just two particles. The research could advance computing and cryptography.

The present study, by researchers at Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, shows that it is possible to generate a single pair of elementary particles (such as photons) that could exist in hundreds of states.

Researchers explained the phenomenon as two Schrödinger cats existing in different dimensions Schrödinger's cat is a thought experiment, which describes the plight of a cat that's locked up in a box containing poison.

"We have two Schrödinger cats which could be alive, dead, or in 101 other states simultaneously," joked Marcus Huber, researcher from the UAB Department of Physics and one of the study authors. "Plus, they are entangled in such a way that what happens to one immediately affects the other."

In quantum physics, particles can remain connected in the same state, despite being far away from each other. Albert Einstein called the phenomenon "spooky action at a distance."

Another striking feature of quantum particles is that they can be in multiple states such as "up," "down," or "both". Researchers working on developing quantum computers have tried to use quantum particles (such as qubits) and connected them to make a system that could process information.

Recently, Thomas Monz and colleagues created entangled states with 14 qubits.

Quantum bits or qubits can exist in superposition, meaning that they can be a 0 or a 1 and everything in-between simultaneously.

A major problem of using several entangled qubits is that a large system is difficult to control.

In the present study, researchers wanted to lower the number of particles used, but increase the number of dimensions. Previous record for entangled particles was 11 dimensions.

The team was able to generate a pair of quantum particles that had over a hundred dimensions instead of just three states seen in qubits.

Researchers say that the new study could advance secure quantum computing.

"This high dimension quantum entanglement offers great potential for quantum information applications. In cryptography, for example, our method would allow us to maintain the security of the information in realistic situations, with noise and interference. In addition, the discovery could facilitate the experimental development of quantum computers, since this would be an easier way of obtaining high dimensions of entanglement with few particles", explained UAB researcher Marcus Huber in a news release.

In the next part of the study, researchers will try to control the different states in order to construct a quantum computer, GigaOm reported.

The study is published in the journal Proceedings of the National Academy of Sciences.