Analysis of electromagnetic propagation in the magnetic plasma state in spin-ice systems

Abstract

Low energy excitation states in magnetic structures of the so-called spin-ices are produced via spin flips among contiguous tetrahedrons of their crystal structure. When there are sufficient free positive and negative charges, the system behaves as a magnetic plasma, which could correspond to the highest temperature peak of the specific heat. The electromagnetic waves in both unconfined and confined systems (waveguides) filled with materials of magnetic charges can be able to transmit information and energy. The only problem is the low temperature for which these magnetic entities appear in the spin-ice materials. However, similar behaviour may be present in other compounds at higher temperatures. This analysis is addressed to study physical properties which should be present in those new materials. Therefore, in this paper, we obtain some magnetic linear responses, the effective masses of the magnetic charges from the precession movement of the monopoles which coincides with a strong electromagnetic absorption frequency, the plasmonic physical magnitude which is identified with the cut propagation frequency in a wave guide, and other properties of the electromagnetic propagation in these compounds with effective magnetic monopoles such as the modification of the electromagnetic fields of the wave in the presence of magnetic charges and currents. All these electromagnetic properties can serve as tests for detecting magnetic entities which mimic the behaviour of magnetic monopoles in other different new materials. Besides, these analyses can be illuminating for obtaining possible circuital applications of these materials that lead to “Magnetronic” devices.

Magnetic charge's relaxation propelled electricity in two-dimensional magnetic honeycomb lattice

“…The flexibility in tuning constituting element's size, hence the inter-elemental dipolar interaction energy, in an artificial magnetic honeycomb lattice can be exploited to generate magnetic charge defects at high temperature. Previously, magnetic charge defect was shown to mediate electrical conduction in a spin ice material via the interaction between electron's spin, s , at the Fermi surface and the transverse local fluctuation in magnetic field B(k) due to the monopole dynamics ( Chern et al., 2013 ; Lopez-Bara and Lopez-Aguilar, 2017 ). According to the formulation, magnetic charge defect's relaxation time plays crucial role in temperature-dependent magnetic charge-mediated conduction, in addition to the residual purely electrical conduction.…”

The contribution of magnetic monopoles to the ponderomotive force

“…Then, to evaluate the ponderomotive force (19) we make use of ( 13) and (17). Keeping ourselves in the slowly-varying regime…”

“…In addition to different experimental attempts to detect these particles (see e.g. [12][13][14]), several studies have shown the effect of hypothetical magnetic monopoles in different aspects of physics such as astrophysics [10,15], high energy physics [16,17], spin ice, [18][19][20][21] and plasma physics [22][23][24][25][26][27][28][29].…”

Two fluid model in low energy excited states within spin-ice systems

“…The values of the n 0 and m can be obtained from indirect experimental results arising from the magnetic conductivity (see refs 7,8 and references therein) they may be between 0.25 and 0.75 in the case without first order phase transition. The energies b and b′ are those energies which do not depend on the increasing of the probability of appearance of the magnetic charges due to the temperature evolution.…”

“…The properties that present these modifications of their magnetic structures could have a double interest: on one hand, it could allow us to discover new characteristics for low-energy excitation states within the magnetic theory and on the other hand, could imply that these compounds were serious candidates for devices capable of propagating both information and energy 3,7,8 . The compounds of Holmium or Disprosium Dy 2 Ti 2 O 7 and Dy 2 Ti 2 O 7 , which crystallize in a pyrochlore type [refs 3,4 and references therein] present a magnetic structure whose main characteristic is that spin-flips in the magnetic moments of the lanthanide ions placed in the vertexes shared by contiguous tetrahedrons can progress in their crystal structures.…”