From Thermodynamics to Information: Landauer’s Limit and Negentropy Principle Applied to Magnetic Skyrmions

Abstract

Magnetic skyrmions are topological swirling spin textures objects that can be manipulated and employed as information carriers. This is accomplished based either on their ground-state properties or their thermodynamic properties. Landauer’s principle establishes an irreversible conversion from information to physics. The inverse mechanism, the inverse mechanism is proposed for magnetic topological defects forming in magnetic nanostructures that are regarded as closed thermodynamic systems confirming Szilard’s and Brillouin’s hypotheses. This mechanism consists of the creation of bits of information using a thermodynamic source having a form of negentropy. In this perspective article, the following are proved for magnetic skyrmions: 1) Landauer’s principle expressed in terms of negentropy and 2) the generalized second principle of thermodynamics based on Brillouin’s negentropy principle of information. The thermodynamic entropy is converted into information entropy at the expense of negentropy, “negative entropy” corresponding to the loss of thermodynamic entropy from the magnetic skyrmion itself. A recently proposed practical device enables the verification of points 1) and 2) and allows a full understanding of the interchange between thermodynamics and information and vice versa regarding skyrmions as information units and showing, in perspective, the considerable advantages offered by this type of storing and coding information.

Quantitative predictive theories through integrating quantum, statistical, equilibrium, and nonequilibrium thermodynamics

“…the sum of probabilityweighted entropy of each configuration. Similar discussions were presented in the literature such as recently by Zivieri [117] by considering the conversion of the thermodynamic 39)), with the negentropy or 'negative entropy' corresponding to the loss of thermodynamic entropy from the magnetic skyrmion which are topological swirling spin textures of individual configurations employed as information carriers, i.e.…”

Releasing antiferromagnetic skyrmions from local magnetic-anisotropy defects

“…They are typically a few nanometers in diameter and can be found in several magnetic materials due to competing Heisenberg exchange and Dzyaloshinskii-Moriya interactions (DMI). These stable structures are essential choices for storing information in upcoming technological devices [1][2][3][4][5][6][7][8][9][10][11][12]. Application of an electric current may record, read and erase skyrmions [13][14][15].…”

“…Application of an electric current may record, read and erase skyrmions [13][14][15]. Additionally, coding information based on the information entropy may be employed in prospect for improving data transmission [12].…”

Landauer Bound and Continuous Phase Transitions

“…A bit of information is obtained by the demon at the price of some negative entropy lost in the environment, which allows the demon to make choices which decrease the entropy in the environment. The relation between the negentropy and the Landauer limit was analyzed in [8,9] considering a system of magnetic skyrmions. There, it was shown that the Landauer bound can be seen as a variation of the negentropy of the skyrmion.…”