Terahertz magneto-optical properties of bi- and tri-layer graphene

Abstract

Magneto-optical (MO) properties of bi- and tri-layer graphene are investigated utilizing terahertz time-domain spectroscopy (THz TDS) in the presence of a strong magnetic field at room-temperature. In the Faraday configuration and applying optical polarization measurements, we measure the real and imaginary parts of the longitudinal and transverse MO conductivities of different graphene samples. The obtained experimental data fits very well with the classical MO Drude formula. Thus, we are able to obtain the key sample and material parameters of bi- and tri-layer graphene, such as the electron effective mass, the electronic relaxation time and the electron density. It is found that in high magnetic fields the electronic relaxation time τ for bi- and tri-layer graphene increases with magnetic field B roughly in a form [Formula: see text]. Most importantly, we obtain the electron effective mass for bi- and tri-layer graphene at room-temperature under non-resonant conditions. This work shows how the advanced THz MO techniques can be applied for the investigation into fundamental physics properties of atomically thin 2D electronic systems.

Magneto‐optical properties of monolayer MoS2‐SiO2/Si structure measured via terahertz time‐domain spectroscopy

“…Therefore, we can employ the theoretical formula of MO conductivity for free electrons in the understanding of the experimental results. It is known that the MO Drude model [ 26 ] is the simplest formula to describe the MO conductivity. However, it cannot reproduce the wavy like dependence of σ 1 ( ω ) upon the radiation frequency in the presence of a magnetic field (see Figure 6).…”

“…The details of the THz TDS system used in this study have been documented previously. [ 26,27,35 ] In the experimental setup (see Figure 3), the fs fiber laser is divided into the pump and probe beams. The pump beam is used for generating the THz radiation source and the probe beam is applied, after a time delay, for THz detection.…”

“…Moreover, in the presence of the external magnetic field, THz TDS can be utilized to measure the real and imaginary parts of the longitudinal and transverse magneto‐optical (MO) conductivities for an electronic material. [ 26 ] Therefore, the MO measurement on the basis of THz TDS can provide more information about the physical properties of an electronic material.…”

Optoelectronic Properties of Monolayer Hexagonal Boron Nitride on Different Substrates Measured by Terahertz Time-Domain Spectroscopy

“…Very recently, we measured the key sample and material parameters such as electronic relaxation time, carrier density and electronic localization factor in ML MoS 2 placed on different commonly used substrates [23] and in La 0.33 Pr 0.34 Ca 0.33 MnO 3 thin films [24] by using THz TDS measurements. Using this technique, we have also examined the Faraday rotation effect and obtained the effective electron masses in biand tri-layer graphene in the presence of a magnetic field [25]. In this study, we generalize the THz TDS technique we used previously to the investigation of the optoelectronic properties of ML hBN.…”

Polarization properties of few-layer graphene on silicon substrate in terahertz frequency range

“…It has been shown that the Faraday rotation is due to the plasmonic coupling in the graphene disks. Mei et al [24] theoretically and experimentally studied the magneto-optical properties of a BLG and a trilayer graphene (TLG) on quartz substrates, in the frequency range from 0.1 to 2.0 THz. Grebenchukov et al [25] theoretically studied the magneto-optical properties of a multilayer graphene (MLG) on a dielectric substrate, at the frequency of 1.0 THz.…”