Finnish and Chinese researchers have prevented quantum information disappearance for the first time.
The Turku Centre for Quantum Physics at the University of Turku, Finland, and the University of Science and Technology of China have proved that quantum information disappearance can be prevented in some cases, and have showed how to control quantum information which leaks from its quibit into the environment.
What is quantum information and how is it used?
Quantum mechanics describes the behaviour of minute physical systems. Quantum mechanics is useful because properties such as mechanical entanglement can be utilised in technology such as quantum computing. Quantum physicists have faced the problem of quantum information disappearance, after it is lost into the environment. It is essential for physicists to understand how quantum information disappearance occurs and to learn how to prevent this from happening.
How has the research benefitted quantum physics?
Professor Chuan-Feng Li from the University of Science and Technology of China said: “Our work is based on exploring the properties of photons and their careful control in the laboratory. In order to achieve the result, it was crucial to first theoretically understand how to create an adequate connection between the polarisation and frequency of the photon in the beginning, and then implement it in the laboratory using extremely refined and challenging experimental techniques.”
Li added: “When the photon serving as the qubit – and its environment – has first been initialised into the right state, it is then possible to arbitrarily control how the information carried by the qubit disappears or is retrieved, and it can even be trapped or protected from disturbances.”
According to University Research Fellow Jyrki Piilo from the Department of Physics and Astronomy of the University of Turku, the study has led to several developments in quantum mechanics. These are:
• Individual photons can now be used to simulate the behaviour of other quantum-mechanical systems such as magnetic spin systems
• The researchers have gained fundamental information on the behaviour of open quantum systems in different environments
• The results enable the manufacture of artificial environments for quibits
How does quantum information disappear?
Quantum mechanical properties are very fragile and usually disappear quickly due to decoherence and quantum noise. This causes the quantum information carried by the quibit to leak into the environment and disappear.