Magnetic detectability of a finite size paramagnet/superconductor cylindrical cloak

Abstract

Cloaking of static magnetic fields by a finite thickness type-II superconductor tube surrounded by a coaxial paramagnet shell is studied. On the basis of exact solutions to the London and Maxwell equations, it is shown that perfect cloaking is realizable for arbitrary geometrical parameters including the thin film case for both constituents. In contrast to the previous approximate studies assuming perfect diamagnetism of the superconductor constituent, it is proven that cloaking provides simultaneously full undetectability, that is the magnetic moment of the structure completely vanishes as well as all high-order multipole moments as soon as the uniform field outside remains unaffected.

Magnetic Illusion: Transforming a Magnetic Object into Another Object by Negative Permeability

“…Magnetic metamaterials [17][18][19] have recently been developed, enabling the realization of novel devices for controlling magnetic fields [19][20][21][22][23][24][25][26][27][28]. They include cloaks that make objects magnetically undetectable [19][20][21][22][23] and shells that concentrate magnetic energy in a given spatial region [24,25]. However, illusion has not been realized for static magnetic fields until now.…”

“…The main obstacle for this realization has been the absence of passive materials with negative static permeability [29].If such negative-µ materials were available, they would allow the realization of novel tools for controlling magnetic fields, including the illusion of transforming the magnetic signature of an object into other ones. Such magnetic illusions could enable the transformation of an original object into: i) a different magnetic object (e. g. disguising a ferromagnet as a superconductor), ii) the same material with different dimensions (enlarging or shrinking the original object [30,31]), iii) air (making the original object magnetically invisible [19][20][21][22][23]).…”

Effect of shear stress on electromagnetic behaviors in superconductor-ferromagnetic bilayer structure

“…39 Based on the London equation and critical state model, the magnetic cloaking behaviours in paramagnet/superconductor shell were studied. 40,41 The longdistance transfer of the magnetic field and magnetic concentrator was also studied. 42,43 During the above investigations, the magnetomechanical coupling behaviour has not been considered.…”

Negative permeability in magnetostatics and its experimental demonstration

“…Following the discovery of transformation optics technique and the development of metamaterials for the control of electromagnetic waves [1][2][3], magnetic metamaterials have recently been introduced. They have led to interesting new properties and devices for controlling magnetostatic fields [4,5], including magnetic cloaks [4,[6][7][8][9][10][11][12][13], magnetic concentrators [14][15][16][17][18][19], and other novel magnetic phenomena [5,[20][21][22]. The use of metamaterials is particularly attractive in magnetostatics because of at least two properties.…”