The low-temperature properties and crossover phenomena of d-dimensional
transverse Ising-like systems within the influence domain of the quantum
critical point are investigated solving the appropriate one-loop
renormalization group equations. The phase diagram is obtained near and at
d=3 and several sets of critical exponents are determined which describe
different responses of a system to quantum fluctuations according to the way of
approaching the quantum critical point. The results are in remarkable agreement
with experiments for a wide variety of compounds exhibiting a quantum phase
transition, as the ferroelectric oxides and other displacive systems.Comment: 36 pages, 2 figures, accepted in Physica