Optical and magneto-optical properties of ferromagnetic monolayer CrBr${}_3$: A first-principles $GW$ and $GW$ plus Bethe-Salpeter equation study

Abstract

The discovery of atomically thin two-dimensional (2D) magnetic semiconductors has triggered enormous research interest recently. In this work, we use first-principles many-body perturbation theory to study a prototypical 2D ferromagnetic semiconductor, monolayer chromium tribromide (CrBr${}_3$). With broken time-reversal symmetry, spin-orbit coupling, and excitonic effects included through the full-spinor $GW$ and $GW$ plus Bethe-Salpeter equation ($GW$-BSE) methods, we compute the frequency-dependent layer polarizability tensor and dielectric function tensor that govern the optical and magneto-optical properties. In addition, we provide a detailed theoretical formalism for simulating magnetic circular dichroism, magneto-optical Kerr effect, and Faraday effect, demonstrating the approach with monolayer CrBr${}_3$. Due to reduced dielectric screening in 2D and the localized nature of the Cr $d$ orbitals, we find strong self-energy effects on the quasiparticle band structure of monolayer CrBr${}_3$ that give a 3.8 eV indirect band gap. Also, excitonic effects dominate the low-energy optical and magneto-optical responses in monolayer CrBr${}_3$ where a large exciton binding energy of 2.3 eV is found for the lowest bright exciton state with excitation energy at 1.5 eV. We further find that the magneto-optical signals demonstrate strong dependence on the excitation frequency and substrate refractive index. Our theoretical framework for modeling optical and magneto-optical effects could serve as a powerful theoretical tool for future study of optoelectronic and spintronics devices consisting of van der Waals 2D magnets.

References in corpus (39)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit
• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• Optimized norm-conserving Vanderbilt pseudopotentials
• Tunable Band Gap and Anisotropic Optical Response in Few-layer Black Phosphorus
• Wannier90 as a community code: new features and applications
• Optical Spectrum of MoS${}_2$: Many-body Effects and Diversity of Exciton States
• Electrical Control of 2D Magnetism in Bilayer CrI3
• Giant Tunneling Magnetoresistance in Spin-Filter van der Waals Heterostructures
• Controlling magnetism in 2D CrI3 by electrostatic doping
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• BerkeleyGW: A Massively Parallel Computer Package for the Calculation of the Quasiparticle and Optical Properties of Materials and Nanostructures
• Ab initio calculation of excitonic effects in the optical spectra of semiconductors
• Probing magnetism in 2D van der Waals crystalline insulators via electron tunneling
• Electric-field switching of two-dimensional van der Waals magnets
• On the origin of magnetic anisotropy in two dimensional CrI${}_3$
• Strain-tunable magnetic anisotropy in monolayer CrCl${}_3$, CrBr${}_3$, and CrI${}_3$
• Electric-field control of magnetism in few-layered van der Waals magnet
• Direct observation of van der Waals stacking dependent interlayer magnetism
• Switching 2D Magnetic States via Pressure Tuning of Layer Stacking
• Pressure-controlled interlayer magnetism in atomically thin CrI3
• Giant and nonreciprocal second harmonic generation from layered antiferromagnetism in bilayer CrI3
• Crystal and Magnetic Structures in Layered, Transition Metal Dihalides and Trihalides
• Direct photoluminescence probing of ferromagnetism in monolayer two-dimensional CrBr3
• Valley Manipulation by Optically Tuning the Magnetic Proximity Effect in WSe${}_2$/CrI${}_3$ Heterostructures
• Ligand-field helical luminescence in a 2D ferromagnetic insulator
• Truncation of Periodic Image Interactions for Confined Systems
• Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides
• Density functional perturbation theory for gated two-dimensional heterostructures: Theoretical developments and application to flexural phonons in graphene
• Coulomb-hole summations and energies for GW calculations with limited number of empty orbitals: a modified static remainder approach
• Physical origin of giant excitonic and magneto-optical responses in two-dimensional ferromagnetic insulators
• Magnetic Two-Dimensional Chromium Trihalides: A Theoretical Perspective
• Micromagnetometry of two-dimensional ferromagnets
• Non-uniform sampling schemes of the Brillouin zone for many-electron perturbation-theory calculations in reduced dimensionality
• Magneto-optical response of chromium trihalide monolayers: chemical trends
• Observation of the polaronic character of excitons in a two-dimensional semiconducting magnet $\mathrm{Cr}{\mathrm{I}}_3$
• Crystal field splitting in Sr${}_{n+1}$Ir${}_n$O${}_{3n+1}$ ($n$ = 1, 2) iridates probed by x-ray Raman spectroscopy
• Quasiparticle Energies and Excitonic Effects of Chromium Trichloride: from Two Dimensions to Bulk

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• Enhanced Magnetization by Defect-Assisted Exciton Recombination in Atomically Thin CrCl${}_3$
• Band-spin-valley coupled exciton physics in antiferromagnetic MnPS${}_3$
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