Effect of electron-hole asymmetry on optical conductivity in 8-Pmmn borophene

Abstract

We present a detail theoretical study of the Drude weight and optical conductivity of 8-$Pmmn$ borophene having tilted anisotropic Dirac cones. We provide exact analytical expressions of $xx$ and $yy$ components of the Drude weight as well as maximum optical conductivity. We also obtain exact analytical expressions of the minimum energy (${\epsilon }_1$) required to trigger the optical transitions and energy (${\epsilon }_2$) needed to attain maximum optical conductivity. We find that the Drude weight and optical conductivity are highly anisotropic as a consequence of the anisotropic Dirac cone. The optical conductivities have a nonmonotonic behavior with photon energy in the regime between ${\epsilon }_1$ and ${\epsilon }_2$, as a result of the tilted parameter $v_t$. The tilted parameter can be extracted by knowing ${\epsilon }_1$ and ${\epsilon }_2$ from optical measurements. The maximum values of the components of the optical conductivity do not depend on the carrier density and the tilted parameter. The product of the maximum values of the anisotropic conductivities has the universal value $(e^2/4\hslash {)}^2$. The tilted anisotropic Dirac cones in 8-$Pmmn$ borophene can be realized by the optical conductivity measurement.

6 pages, 3 figures, to appear in Physical Review B

References in corpus (7)

• Measurement of the Optical Conductivity of Graphene
• The optical conductivity of graphene in the visible region of the spectrum
• Tilted anisotropic Dirac cones in quinoid-type graphene and alpha-(BEDT-TTF)_2I_3
• Sum Rules for the Optical and Hall Conductivity in Graphene
• Electronic properties of 8-Pmmn borophene
• Strain-induced pseudomagnetic field in Dirac semimetal borophene
• Optical Signatures of the Tunable Band Gap and Valley-Spin Coupling in Silicene

Cited by in corpus (8)

• Signature of tilted Dirac cones in Weiss oscillations of $8-Pmmn$ borophene
• Optical properties of massive anisotropic tilted Dirac systems
• Anisotropic longitudinal optical conductivities of tilted Dirac bands in 1T${}^{\prime }$-MoS${}_2$
• Anomalous caustics and Veselago focusing in 8-Pmmn borophene p-n junctions with arbitrary junction directions
• Synthetic non-Abelian gauge fields and gravitomagnetic effects in tilted Dirac cone systems
• Mini Band Gap Generation in Magnetic Beta-Borophene: Effects of Optical Phonon Interaction
• Floquet spectrum and electronic transitions of tilted anisotropic Dirac materials under electromagnetic radiation: monodromy matrix approach
• Strong anisotropic optical properties of 8-Pmmn borophene: a many-body perturbation study