The following article appeared in Physics World, vol. 12, no. 4, pg 33 (1999). Additional footnotes [9,10] have been added to the web version.
Phase transitions are normally associated with changes of temperature but a new type of transition - caused by quantum fluctuations near absolute zero - is possible, and can tell us more about a wide range of systems in condensed matter physics
2 Quantum Ising systems
3 High-temperature superconductors
4 Spins and stripes
5 Experiments on superconductors
6 Quantum Hall systems