Quantum first-order phase transitions

The scaling theory of critical phenomena has been successfully extended for classical first-order transitions even though the correlation length does not diverge in these transitions. In this paper, we apply the scaling ideas to quantum first-order transitions. The usefulness of this approach is illustrated treating the problems of a superconductor coupled to a gauge field and of a biquadratic Heisenberg chain, at zero temperature. In both cases there is a latent heat associated with their discontinuous quantum transitions. We discuss the effects of disorder and give a general criterion for itʹs relevance in these transitions.