Magnetic-field controlled anomalous refraction in doped semiconductors

Abstract

We predict here that a slab made of a doped semiconductor can exhibit anomalous refraction under the application of a static magnetic field. This anomalous refraction takes place in the far-infrared range and it occurs for any angle of incidence. We show that this effect is due to the fact that a doped semiconductor under a magnetic field can behave, to some extent, as a hyperbolic metamaterial. We also show that the occurrence of this anomalous refraction enables a semiconductor slab under a magnetic field to partially focus the electromagnetic radiation. The remarkable thing in our case is that we deal with naturally occurring materials and the anomalous refraction can be tuned at will with an external field.

Magnetic field effects in the near-field radiative heat transfer between planar structures

“…Thus, one can see that there are regions at finite external field in which the real parts of 1 and 3 , which mainly determine the diagonal components of the permittivity tensor, have opposite signs. This fact implies the appearance of hyperbolic modes, as it has been discussed before [33,39].…”

“…Another interesting question is related to the magnetic field dependence of the NFRHT between structures containing thin films of MO materials. As we discovered in the case of doped semiconductors, the application of a magnetic field in these materials leads to the appearance of hyperbolic modes [33,39], very much like in hyperbolic metamaterials where the diagonal components of the permittivity tensor have different signs [40]. These hyperbolic modes where shown to play a very important role in the field-dependent NFRHT between doped semiconductors [33], and since they are propagating waves, they are expected to be very sensitive to the presence of substrates in structures containing thin films.…”

Near-field radiative heat transfer between one-dimensional magneto-photonic crystals

“…These regions are characterized by the existence of electromagnetic modes, known as hyperbolic modes, that are propagating inside the InSb and evanescent out of it. These modes are responsible of the progressive disappearance of the SPP modes occurring below the surface plasmon frequency ω sp = ω p / √ 2, and of the SPhP modes occurring between the longitudinal and transverse optical frequencies ω T and ω L , as it has been shown for infinite parallel plates and thin films made of InSb [32,39].…”

“…[37] in a very asymmetric situation. The reason for this reduction in extended systems (like infinite parallel plates) is that a magnetic field induces the appearance of hyperbolic modes that replace the surface modes, both surface plasmon polaritons (SPPs) and surface phonon polaritions (SPhPs), that dominate the NFRHT in these systems in the absence of magnetic field [32,39]. These hyperbolic modes, in spite of being propagating inside the material, are less effective than surface modes transferring the heat across the gap between two bodies.…”

Near-field radiative heat transfer between one-dimensional magnetophotonic crystals

“…[37] in a very asymmetric situation. The reason for this reduction in extended systems (like infinite parallel plates) is that a magnetic field induces the appearance of hyperbolic modes that replace the surface modes, both surface plasmon polaritons (SPPs) and surface phonon polaritions (SPhPs), that dominate the NFRHT in these systems in the absence of magnetic field [32,39]. Let us remember that hyperbolic modes can appear in uniaxial materials described by a dielectric tensor of the form ˆ = diag{ xx , xx , zz }, which leads to the following dispersion relation for transversal magnetic (TM) polarization:…”