Giant tunable Faraday effect in a semiconductor magneto-plasma for broadband terahertz polarization optics

Abstract

Abstract:We report on a giant Faraday effect in an electron plasma in nInSb probed via polarization-resolved terahertz (THz) time-domain spectroscopy. Polarization rotation angles and ellipticities reach as large as π/2 and 1, respectively, over a wide frequency range (0.3-2.5 THz) at magnetic fields of a few Tesla. The experimental results together with theoretical simulations show its promising ability to construct broadband and tunable THz polarization optics, such as a circular polarizer, half-wave plate, and polarization modulators.

A table-top, repetitive pulsed magnet for nonlinear and ultrafast spectroscopy in high magnetic fields up to 30 T

“…Depending on the data acquisition speed, experiments that require the magnetic field dependence can be swept from 0-30 T within a single magnet pulse, and then repeated to improve the signal-to-noise ratio by averaging. The optical access via interchangeable windows allows us to introduce a variety of wavelengths, and, importantly, the application most suited for this magnet will be time-domain terahertz spectroscopy [7][8][9][10][11][12][13][14][15] because of the compact design and direct optical access to the sample. Furthermore, the direct optical access allows polarizationsensitive measurements 14,44 without the complications that arise with optical fibers.…”

“…The optical access via interchangeable windows allows us to introduce a variety of wavelengths, and, importantly, the application most suited for this magnet will be time-domain terahertz spectroscopy [7][8][9][10][11][12][13][14][15] because of the compact design and direct optical access to the sample. Furthermore, the direct optical access allows polarizationsensitive measurements 14,44 without the complications that arise with optical fibers. Finally, the mini-coil design can be reproduced by other researchers around the world and incorporated into setups that already use expensive ultrafast laser systems or other sophisticated optical systems, greatly expanding the availability of high magnetic fields for condensed matter and materials research.…”

“…Combining access to applied magnetic fields with ultrafast spectroscopy techniques and/or intense, pulsed laser sources can provide a wealth of information in condensed matter physics, including many-body interactions and Coulomb correlations in semiconductors in the quantum Hall regime, 1-3 optical properties of exotic materials and/or semiconductor magneto-plasmas in the terahertz frequency range, [4][5][6][7][8][9][10][11][12][13][14][15] and ultrafast spectroscopy and control of magnetization in magnetic semiconductors and ferromagnets. [16][17][18] Typically, experimental access to magnetic fields up to 30 T are limited to special facilities in the form of national laboratories.…”

Review of Anisotropic Terahertz Material Response

“…Narrow-gap semiconductors and semimetals show giant free-carrier Faraday effect in the THz frequency range [20][21][22]. Here, we review recent reports on the giant Faraday effects observed in n-InSb, HgTe, and grapheme in the THz frequency range and discuss their potential as THz polarization optics, such as circular polarizers, wave plates, isolators, and modulators.…”

Magnetically tunable terahertz magnetoplasmons in ferrofluid-filled photonic crystals

“…In spite of this, some recent progresses in this field have been reported. For examples, the giant Faraday rotations were observed in some high electron mobility semiconductors, such as InSb, 8 HgTe, 9 and graphene. 10 A magnetically induced THz transparency (a sudden appearance and disappearance for THz transmission) in the n-doped InSb was demonstrated, owing to the interference between left and right circularly polarized magnetoplasmon (MP) eigenmodes.…”