Updated: Jan 1, 2020
Development in technologies capable of processing information based on the laws of Quantum Physics can make a profound impact on modern society. The most common example includes Quantum Computers that hold the key to solving problems considered far too complex for even the most powerful supercomputers of today. Whereas, quantum internet can help protect the entire worlds’ information from malware attacks.
However, in order to do that, one would need to control and effectively measure the flow of quantum information, which is typically encoded in single quantum particles.
The scientists from the University of Bristol, and those belonging to the Denmark Technical University, have been able to develop some chip-scale devices that have the capability to harness the applications of quantum physics by manipulation of light particles within a programmable nano-scale circuit.
Scientists were able to encode quantum information in light particles that were manipulated inside the circuit and process it with high efficiency and low noise. This demonstration is said to boost the ability for production of more complex quantum circuits to help in quantum computing and communication.
One more of the breakthrough experiments conducted by researchers at the Bristol University's Quantum Engineering Technology Labs also demonstrated Quantum Teleportation of information between two different programmable chips for the very first time. This transfer of information proves to be a cornerstone in quantum communication and computing.
Quantum Teleportation is a process that allows quantum state transfer of quantum particles from one place to another by entanglement which is a quite challenging process. The process comes handy not only in communication but also serves as a basic building block of optical quantum computing.
Dan Llewellyn, a co-author from Bristol said they were able to demonstrate a high-quality entanglement link across two different chips where photons shared a single quantum state. Each chip was fully programmed to perform a range of demonstrations utilising entanglement.
The demonstration process constituted a two chip Teleportation experiment in which the individual quantum state of a particle was transmitted across two chips after a Quantum measurement. This measurement was focused on utilising the behaviour of quantum physics that tends to both collapse the entanglement link and transfer the particle state to another on a receiver chip at the same time.
Adding to Dan's statement, Dr Imad Faruque, another co-author from Bristol said that they had developed a complex circuit with four sources, based on their previous result of on-chip high-quality single-photon sources. These sources were tested and were found very identical as they emitted identical photons, a highly essential criterion for conducting the experiment.
The results of the experiment showed a 91% high-fidelity quantum teleportation rate. The researchers also demonstrated other functionalities of their design such as entanglement swapping that is useful in quantum networks and quantum repeaters, and four-photon GHZ states, useful in quantum computing and quantum internet.
Dr Yunhong Ding, co-author from DTU said that stability, low loss and control are important factors for integrated quantum photonics. According to him, the reason behind the success of this experiment was the state-of-the-art low-loss silicon photonics technology that is based on high-quality fabrication. Whereas, Dr Jianwei Wang, the lead author who works at Peking University now, said they are looking to have a single silicon chip integration of classical electronic controls with quantum photonic devices to facilitate chip-based CMOS-compatible information processing network for quantum communication.