Rolf Landauer first proposed the principle in 1961 while working at
IBM. He justified and stated important limits to an earlier conjecture by
John von Neumann. This refinement is sometimes called the Landauer bound, or Landauer limit. In 2008 and 2009, researchers showed that Landauer's principle can be derived from the
second law of thermodynamics and the entropy change associated with information gain, developing the thermodynamics of quantum and classical feedback-controlled systems. In 2011, the principle was generalized to show that while information erasure requires an increase in entropy, this increase could theoretically occur at no energy cost. Instead, the cost can be taken in another
conserved quantity, such as
angular momentum. In a 2012 article published in
Nature, a team of physicists from the
École normale supérieure de Lyon,
University of Augsburg and the
University of Kaiserslautern described that for the first time they have measured the tiny amount of heat released when an individual bit of data is erased. In 2014, physical experiments tested Landauer's principle and confirmed its predictions. In 2016, researchers used a laser probe to measure the amount of energy dissipation that resulted when a
nanomagnetic bit flipped from off to on. Flipping the bit required about at 300 K, which is just 44% above the Landauer minimum. A 2018 article published in
Nature Physics features a Landauer erasure performed at cryogenic temperatures on an array of
high-spin (
S = 10) quantum
molecular magnets. The array is made to act as a spin register where each nanomagnet encodes a single bit of information. == Challenges ==