Utilising quantum computation to witness phase transitions

This project links the advancing technology of quantum computation, with the fundamental theory of phase transitions in physical systems. Quantum computers use qubits, which utilise a quantum property known as entanglement. Subsequently, quantum computers can perform tasks that classical computers are physically unable to do. Utilising this, quantum computers can be used to witness quantum energy teleportation which is a strictly quantum mechanical effect, therefore classical computation is unable to witness this. The benefit of witnessing quantum energy teleportation is that there is an apparent link between the energy teleported and the corresponding phase transition of the system. The phase transition clarifies the point at which a system undergoes a change in physical behaviour. It is important to understand how physical systems change, as certain phases may provide technological benefit, therefore being able to predict and understand them is of both fundamental and practical interest.

Combining both, the application of quantum computation using quantum energy teleportation, and developing our understanding of phase transitions is the focus of this project. This will be done by computing the quantum energy teleportation for various well-known physical systems, and comparing the results with the known phase transition points. An additional point of interest, is to study these two phenomena from the perspective of quantum information, specifically focusing on how 'quantum' these physical systems are, and how the quantum correlation evolves throughout the process. In particular, a type of quantum correlation will be studied known as quantum discord. This will be compared with entanglement entropy as this also believed to be a good witness of phase transitions. Quantum discord is more general than entanglement, so it is believed that that discord should also be a good witness for phase transitions. This project will also look to link and develop the link between quantum energy teleportation, entanglement entropy, and quantum discord. It is of national interest to understand and quantify quantum correlations, as this will help develop materials which can utilise the advantage gained from quantum correlations.

Subsequently, the aim of this project is to further the current understanding of phase transitions using quantum technologies with an added focus of developing the theory of quantum correlations.