Preprint Article Version 1 This version is not peer-reviewed

# Magnetocaloric Effect in Non-Interactive Electrons Systems: The Landau Problem'' and Its Extension to Quantum Dot

Version 1 : Received: 29 June 2018 / Approved: 2 July 2018 / Online: 2 July 2018 (12:02:51 CEST)

A peer-reviewed article of this Preprint also exists.

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. 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.

Journal reference: Entropy 2018, 20, 557
DOI: 10.3390/e20080557

## Abstract

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 degeneration 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 degeneration 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.

## Subject Areas

magnetocaloric effect; magnetic cycle; thermodynamics