A phase transition is a change that happens to a substance when it goes from one form to another. It can be like when ice melts and becomes water, or when water boils and becomes steam. Full definition
This led to the current question; phase transitions in quantum field theories are well known. (sciencedaily.com)
The system already allows researchers to obtain unique insights into transformations between different types of quantum phases, called quantum phase transitions. (sciencedaily.com)
The new phenomenon is a liquid - liquid phase transition, and until now it had only been seen in computer simulations of water models. (sci-news.com)