Spectroscopic signatures of magnetization-induced band renormalization and strong spin-charge-lattice coupling in EuZn${}_2$As${}_2$

Abstract

We report an infrared spectroscopy study of the antiferromagnetic (AFM) insulator EuZn${}_2$As${}_2$ over a broad frequency range, spanning temperatures both above and below the AFM transition $T_{\mathrm{N}}\simeq$ 20 K. The optical response reveals an insulating behavior, featuring two prominent infrared-active phonon modes at around 95 and 190 cm${}^{-1}$, and two subtle absorption peaks at around 130 ($\alpha$ peak) and 2700 cm${}^{-1}$ ($\beta$ peak), along with a strong absorption edge rising around 9000 cm${}^{-1}$ ($\gamma$ peak). Significantly, the temperature-dependent changes in these peaks show noticeable anomalies across the AFM transition, particularly the emergence of the $\alpha$ peak and an unusual redshift of the $\gamma$ peak, suggesting a strong interaction between the charge excitations and the AFM order. Band structure calculations reveal that these anomalies arise from magnetization-induced band renormalizations, including shifts and foldings. Additionally, both phonon modes feature asymmetric Fano line shapes at low temperatures, with the 95 cm${}^{-1}$ phonon mode exhibiting strong coupling to the fluctuations of Eu spins. These findings highlight a complex interplay of spin, charge, and lattice degrees of freedom in EuZn${}_2$As${}_2$.

arXiv comment6 pages, 4 figures

References in corpus (28)

• Topological Materials: Weyl Semimetals
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Prediction and observation of the first antiferromagnetic topological insulator
• Intrinsic magnetic topological insulators in van der Waals layered MnBi${}_2$Te${}_4$-family materials
• Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator
• Large intrinsic anomalous Hall effect in half-metallic ferromagnet Co3Sn2S2 with magnetic Weyl fermions
• Progress and prospects in magnetic topological materials
• Higher-order Topology of Axion Insulator EuIn${}_2$As${}_2$
• Dirac surface states in intrinsic magnetic topological insulators EuSn2As2 and MnBi2nTe3n+1
• Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd${}_2$As${}_2$
• An ideal Weyl semimetal induced by magnetic exchange
• A Single Pair of Weyl Fermions in Half-metallic EuCd2As2 Semimetal
• In-plane antiferromagnetic moments in axion topological insulator candidate EuIn${}_2$As${}_2$
• Colossal Magnetoresistance without Mixed Valence in a Layered Phosphide Crystal
• Temperature-induced band shift in ferromagnetic Weyl semimetal Co3Sn2S2
• Topological classification and diagnosis in magnetically ordered electronic materials
• Field-induced Topological Hall effect in antiferromagnetic axion insulator candidate EuIn${}_2$As${}_2$
• Anisotropy of the magnetic and transport properties in EuZn${}_2$As${}_2$
• EuCd${}_2$As${}_2$: a magnetic semiconductor
• Colossal magnetoresistance in EuZn${}_2$P${}_2$ and its electronic and magnetic structure
• Consecutive topological phase transitions and colossal magnetoresistance in a magnetic topological semimetal
• Unusual Magnetic Properties in Layered Magnetic Topological Insulator EuSn2As2
• Intrinsic Magnetic Topological Materials
• Single pair of Weyl nodes in the spin-canted structure of EuCd${}_2$As${}_2$
• Topological Hall Effect Driven by Short-Range Magnetic Orders in EuZn${}_2$As${}_2$
• Optical properties and carrier localization in the layered phosphide EuCd${}_2$P${}_2$
• Electronic band reconstruction across the insulator-metal transition in colossal magnetoresistive EuCd2P2
• Recent advances in understanding and manipulating magnetic and electronic properties of Eu$M_2{X}_2$ ($M$ = Zn, Cd; $X$ = P, As)

Cited by in corpus (2)

• Design, synthesis, and physical properties of the intergrowth compound Eu${}_2$CuZn${}_2$As${}_3$
• Temperature Dependent Evolution of the Electronic Structure in EuZn2As2 across the Neel Transition