Phase transiting to a new quantum universe

Recent insight and discovery of a new class of quantum transition opens the way for a whole new subfield of materials physics and quantum technologies.

This week an article in Nature Physics reports the results on quantum properties of ferroelectric crystals, led by Stephen Rowley, together with Siddharth Saxena and Gilbert Lonzarich of the Cavendish Laboratory. They explore a new type of quantum phase transition in these seemingly 'inert' materials.

Quantum phase transitions are subtly different from the familiar classical phase transitions of which an example would be the freezing of water or melting of ice as its temperature is varied. In such a transition, matter transforms into a more or less ordered state depending on whether its temperature is decreased or increased. However, if the temperature was hypothetically fixed at absolute zero and another parameter, such as pressure was applied to bring about a transition, it would occur without any change in entropy, i.e., it would be an 'order to order' transition. In the neighborhood of such a zero entropy phase transition one often finds the emergence of superconductivity or other forms of novel quantum order.