Landauer's principle

The Landauer principle is a hypothesis and states that the deletion of a bit of information necessarily the delivery of a power of

Means in the form of heat to the environment. is the absolute temperature of the environment is the Boltzmann constant. In 1961, formulated by Rolf Landauer principle thus be linked to information theory on the one hand with thermodynamics and statistical physics on the other.

By Landauer principle exists for irreversible working computer as there are today almost everyone, a theoretical lower bound of the power loss. In practice, this is higher until further orders of magnitude. Moore's law can be expected to achieve this limit for 2030-2035. Below this limit can be only with basic technical innovations such as quantum computers or reversible working computers by Charles H. Bennett. The latter are derived directly from the Landauer principle. To avoid erasing information, they run after the end of a calculation backwards back into the initial state. For this purpose, all items must be reversible newly developed by the logic gate to the programming language.

Was also proposed by Charles Bennett, the interpretation of Maxwell's demon with the Landauer principle. From the above formula for the energy loss follows directly for the output when deleting an entropy bits:

This entropy is released by overwriting, so the implicit deletion of the memory of the demon for the speed of the approaching particles. The entropy increase caused thereby raises the reduction caused by its sorting operation on exactly.

Find positive support Landauer's theses in the theoretical work of the American physicist Edwin Thompson Jaynes. Criticism was expressed by the philosopher of science Orly Shenker, according to Landauer inadmissible blended the thermodynamic and information-theoretical entropy.

Landauer's theses are of considerable theoretical significance and form a key building block for a number of further theories, eg in fundamental work on quantum computers. A first experimental confirmation of Landauer's thesis was presented by physicists from Augsburg, Lyon and Kaiserslautern in March 2012. In their experiment, a micro glass sphere was considered in a focused laser light generated by a double -well potential, where 1 bit information of the position in a trough, 0 bit of the position of the ball in the energetically lower trough corresponded. A verification or refutation by other research groups stands out so far. However, it was shown that entanglement and quantum information is a violation of Landauer principle is possible depending on the knowledge that has been an observer of the system on a theoretical level.