By Júlio Bernardes Researchers Júlio Larrea (left) and Fernando Almeida discussing the preparation of the experiment for measuring specific heat under high pressures – Photo: Reproduction of the Article In physics, quantum systems are those in which the behavior of molecules, atoms, and particles cannot be described by any classical model. An example is a quantum system of spins. A spin may be defined as the quantum manifestation of the rotation of electrons (which are particles with electrical charges inside atoms). When several electrons present the same rotation, i.e., the same spin, it is said that the entire system is in the same state, which is called the quantum phase. Changes between quantum phases or quantum phase transitions may occur under extreme conditions of very low temperatures and high pressure and magnetic fields, which renders it impossible to measure their properties such as heat (amount of energy) through traditional techniques. At the USP Institute of Physic...
