Thermodynamics is one of the basic pillars of modern physics.
Despite its great importance for our technological development, the the
validity of very foundations of this theory was always a controversial
issue. In 1871, with the intention to discuss the validity of the second
law of thermodynamics, Maxwell introduced a character that since then
permeates the physics. Maxwell’s demon was apparently able to violate the
second law. There was several attempts of saving this law, but only with
the recognition, due to Rolf Landauer, of the physical character of
information, the demon was finally exorcized. This important result, today
know as the Landauer principle, states that information cannot be erased
without heat generation. Its importance goes beyond the physical science,
playing an important role in biology, computer science and engineering.
However, such principle was only recently experimentally verified for a
classical system. Here we discuss the first experimental implementation of
Landauer’s principle in the full quantum regime.