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Article

Magnetocaloric Effect in Non-Interactive Electron Systems: “The Landau Problem” and Its Extension to Quantum Dots

1
Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso 2340000, Chile
2
Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA), Santiago 8320000, Chile
*
Author to whom correspondence should be addressed.
Entropy 2018, 20(8), 557; https://doi.org/10.3390/e20080557
Received: 29 June 2018 / Revised: 23 July 2018 / Accepted: 24 July 2018 / Published: 27 July 2018
(This article belongs to the Special Issue Entropy: From Physics to Information Sciences and Geometry)
In this work, we report the magnetocaloric effect (MCE) in two systems of non-interactive particles: the first corresponds to the Landau problem case and the second the case of an electron in a quantum dot subjected to a parabolic confinement potential. In the first scenario, we realize that the effect is totally different from what happens when the degeneracy of a single electron confined in a magnetic field is not taken into account. In particular, when the degeneracy of the system is negligible, the magnetocaloric effect cools the system, while in the other case, when the degeneracy is strong, the system heats up. For the second case, we study the competition between the characteristic frequency of the potential trap and the cyclotron frequency to find the optimal region that maximizes the ΔT of the magnetocaloric effect, and due to the strong degeneracy of this problem, the results are in coherence with those obtained for the Landau problem. Finally, we consider the case of a transition from a normal MCE to an inverse one and back to normal as a function of temperature. This is due to the competition between the diamagnetic and paramagnetic response when the electron spin in the formulation is included. View Full-Text
Keywords: magnetocaloric effect; magnetic cycle; thermodynamics magnetocaloric effect; magnetic cycle; thermodynamics
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MDPI and ACS Style

Negrete, O.A.; Peña, F.J.; Florez, J.M.; Vargas, P. Magnetocaloric Effect in Non-Interactive Electron Systems: “The Landau Problem” and Its Extension to Quantum Dots. Entropy 2018, 20, 557. https://doi.org/10.3390/e20080557

AMA Style

Negrete OA, Peña FJ, Florez JM, Vargas P. Magnetocaloric Effect in Non-Interactive Electron Systems: “The Landau Problem” and Its Extension to Quantum Dots. Entropy. 2018; 20(8):557. https://doi.org/10.3390/e20080557

Chicago/Turabian Style

Negrete, Oscar A., Francisco J. Peña, Juan M. Florez, and Patricio Vargas. 2018. "Magnetocaloric Effect in Non-Interactive Electron Systems: “The Landau Problem” and Its Extension to Quantum Dots" Entropy 20, no. 8: 557. https://doi.org/10.3390/e20080557

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