Entangled understanding

16 June 2016

Published in Scientific Reports: RMIT researchers have developed and demonstrated a method capable of efficiently detecting high-dimensional entanglement.

In quantum physics particles are said to be entangled, and part of an entangled system, when the quantum state of one particle determines the quantum state of the other, beyond what is possible according to classical physics.

The quality is important for the development of full scale quantum computing, which heavily relies on entanglement between the individual particles as a way to store information. It promises to vastly increase the amount of information that can be stored and processed with the same number of computation units, which in quantum computing are called qubits.

This is because, contrary to the binary (0,1) form used in current computers to encode information, the high-dimensional entangled state of a particle can encode a message as 0, 1, 2 or more.

However, the drawback is that numerous measurements are required to certify that the system has enough entanglement between the qubits, and at present the tools for characterising high-dimensional entangled states are limited.

The research paper "High-dimensional entanglement certification" describes a new method that requires only two local measurements of complementary properties. The procedure can also certify whether the system is maximally entangled.

According to the authors, their method could significantly cut down on the number of measurements needed as it requires the least number of measurements per dimension and is applicable for systems of any dimension.

Story based on information from RMIT