Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd
            <sub>2</sub>
            As
            <sub>2</sub>

Ma, Junzhang; Nie, Simin; Yi, Changjiang; Jandke, Jasmin; Shang, T.; Yao, Mengyu; Naamneh, Muntaser; Yan, Lei; Sun, Young; Chikina, Alla; Strocov, Vladimir N.; Medarde, M.; Song, Minghao; Xiong, Ye; Xu, Gang; Wulfhekel, Wulf; Mesot, J.; Reticcioli, Michele; Franchini, Cesare; Mudry, Christopher; Müller, Mélanie; Shi, Youguo; Qian, Tian; Ding, Hui; Shi, M.

doi:10.1126/sciadv.aaw4718

Cited by 168 publications

(158 citation statements)

References 46 publications

Supporting

Mentioning

139

Contrasting

Order By: Relevance

“…We hope that our study of dynamical response functions will motivate experimental studies of the spin response of FA states, similar to experiments on bulk WSMs in Ref. [86]. Our work should also be useful for exploring nonlocal transport and optical properties of the FA surface states.…”

Section: Discussionmentioning

confidence: 59%

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Ghosh

Timm

2020

Phys. Rev. B

View full text Add to dashboard Cite

Weyl semimetals exhibit exotic Fermi-arc surface states, which strongly affect their electromagnetic properties. We derive analytical expressions for all components of the composite density-spin response tensor for the surfaces states of a Weyl-semimetal model obtained by closing the band gap in a topological insulating state and introducing a time-reversal-symmetry-breaking term. Based on the results, we discuss the electromagnetic susceptibilities, the current response, and other physical effects arising from the density-spin response. We find a magnetoelectric effect caused solely by the Fermi arcs. We also discuss the effect of electron-electron interactions within the random phase approximation and investigate the dispersion of surface plasmons formed by Fermi-arc states. Our work is useful for understanding the electromagnetic and optical properties of the Fermi arcs. arXiv:2001.00438v2 [cond-mat.mes-hall] 4 Apr 2020

show abstract

Section: Discussionmentioning

confidence: 59%

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Ghosh

Timm

2020

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…The symmetry above and below T N plays an essential role for the band degeneracy and the detailed dispersion evolution, as well as for the topology of the band structure. The comparison of the band structure at 2 and 11 K has been discussed in our previous study 27. In addition to the two temperature points, in Figure we show the ARPES spectra as a function of temperature, approaching and crossing T N .…”

Section: The Number Of Occupied Bands With Even and Odd Parity At Thementioning

confidence: 77%

“…For other surfaces, which do not retain any mirror or

T L

symmetry, the surface states are gapped and the hinge states, associated with higher order TI states, emerge at the edges of these surfaces 25,26. Although the spin fluctuation induced topological Weyl semimetal EuCd 2 As 2 has been uncovered in the paramagnetic phase,27 it still awaits to expose the variety of possible novel topological phases in the AFM ground states.…”

Section: The Number Of Occupied Bands With Even and Odd Parity At Thementioning

confidence: 99%

“…A nonzero Z 4 = 2 index is associated with the nontrivial axion insulator state25 which appears in EuCd 2 As 2 . Because EuCd 2 As 2 has two natural cleavage surfaces,27, i.e., the (001) and (101) surface, it is relevant to calculate the surface states at these surfaces. Protected by the mirror symmetry ( M x ), spins align along the x direction (Figure 5c) and massless Dirac surface states can occur at the (001) surface.…”

Section: The Number Of Occupied Bands With Even and Odd Parity At Thementioning

confidence: 99%

“…When temperature is increased above the T N , the band structure along Γ‐A line agrees well with the FM model calculation rather than AFM DSM states induced by strong FM spin fluctuations. 27…”

Section: The Number Of Occupied Bands With Even and Odd Parity At Thementioning

confidence: 99%

See 2 more Smart Citations

Emergence of Nontrivial Low‐Energy Dirac Fermions in Antiferromagnetic EuCd₂As₂

Wang

Nie

et al. 2020

Advanced Materials

Self Cite

View full text Add to dashboard Cite

Parity‐time symmetry plays an essential role for the formation of Dirac states in Dirac semimetals. So far, all of the experimentally identified topologically nontrivial Dirac semimetals (DSMs) possess both parity and time reversal symmetry. The realization of magnetic topological DSMs remains a major issue in topological material research. Here, combining angle‐resolved photoemission spectroscopy with density functional theory calculations, it is ascertained that band inversion induces a topologically nontrivial ground state in EuCd2As2. As a result, ideal magnetic Dirac fermions with simplest double cone structure near the Fermi level emerge in the antiferromagnetic (AFM) phase. The magnetic order breaks time reversal symmetry, but preserves inversion symmetry. The double degeneracy of the Dirac bands is protected by a combination of inversion, time‐reversal, and an additional translation operation. Moreover, the calculations show that a deviation of the magnetic moments from the c‐axis leads to the breaking of C3 rotation symmetry, and thus, a small bandgap opens at the Dirac point in the bulk. In this case, the system hosts a novel state containing three different types of topological insulator: axion insulator, AFM topological crystalline insulator (TCI), and higher order topological insulator. The results provide an enlarged platform for the quest of topological Dirac fermions in a magnetic system.

show abstract

High‐Mobility Carriers in Germanene Derivatives

Parfenov

Averyanov

Tokmachev

et al. 2020

Adv Funct Materials

View full text Add to dashboard Cite

Buckled elemental analogs of graphene—2D‐Xenes silicene, germanene, and stanene—and their derivatives are predicted to host high‐mobility carriers. Experiments, however, have not as yet confirmed the predictions. Here, high‐mobility (exceeding 104 cm2 V−1 s−1) carriers are discovered in intercalated multilayer germanene. Epitaxial films of antiferromagnetic and diamagnetic MGe2 are synthesized via topochemical reactions, followed by extensive studies of the atomic and magnetic structures. Quantum oscillations in MGe2 resistance manifest quasi‐2D Fermi‐surface pockets with effective masses of carriers as low as 0.015 me, comparable to graphene. The detected signature of the chiral anomaly in magnetoresistance and nonzero Berry phases may indicate the topological nature of the MGe2 electronic structure and charge transport. The discovery bridges the gap between theory and experiment, thus establishing 2D‐Xenes as promising building blocks in materials engineering. Concurrently, the combination of magnetism and high mobility in Eu‐intercalated germanene is attractive for spintronic applications.

show abstract

Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd ₂ As ₂

Cited by 168 publications

References 46 publications

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Emergence of Nontrivial Low‐Energy Dirac Fermions in Antiferromagnetic EuCd₂As₂

High‐Mobility Carriers in Germanene Derivatives

Contact Info

Product

Resources

About

Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd 2 As 2

Cited by 168 publications

References 46 publications

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Emergence of Nontrivial Low‐Energy Dirac Fermions in Antiferromagnetic EuCd2As2

High‐Mobility Carriers in Germanene Derivatives

Contact Info

Product

Resources

About

Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd ₂ As ₂

Emergence of Nontrivial Low‐Energy Dirac Fermions in Antiferromagnetic EuCd₂As₂