Incommensurate Transverse Peierls Transition and Signature of Chiral Charge Density Wave in EuAl4
Year: 2025
Type: article
Abstract: In one-dimensional quantum materials, electrons and lattices can undergo a Peierls transition, a translational symmetry-breaking instability traditionally understood through electron coupling to longitudinal acoustic phonons. Recently, this paradigm has been revised in topological semimetals, where transverse acoustic phonons couple to p-orbital electrons, giving rise to a transverse Peierls transition. Importantly, transverse Peierls transition-induced distortions can further break mirror or inversion symmetries, producing nematic or chiral charge density waves. Here, we report the experimental identification of an incommensurate transverse Peierls transition in EuAl4. Using meV-resolution inelastic x-ray scattering, we observe complete softening of a transverse acoustic phonon upon cooling, while the longitudinal acoustic mode remains unaffected. First-principles calculations reveal that the transverse Peierls transition wavevector coincides with a charge susceptibility peak connecting nested Dirac bands. Second harmonic generation confirms mirror symmetry breaking, supporting a chiral charge density wave stabilized by the transverse Peierls transition. A transverse Peierls transition can occur when transverse acoustic phonons couple with conducting p-orbital electrons. Here, the authors observe an incommensurate transverse Peierls transition and signatures of a chiral charge density wave in EuAl4.
Source: Nature Communications
Institutions: Oak Ridge National Laboratory, The University of Texas at Austin, University of Michigan, University of Tennessee at Knoxville, University of Illinois Urbana-Champaign, The Hong Kong University of Science and Technology (Guangzhou), Argonne National Laboratory, Advanced Photon Source, Brookhaven National Laboratory, National Synchrotron Light Source II, Chinese Academy of Sciences, Institute of Theoretical Physics, Center for Nanophase Materials Sciences, Hong Kong University of Science and Technology
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: National Science Foundation, U.S. Department of Energy, University of Michigan, University of Texas at Austin, Office of Science, Department of Mechanical Engineering, University of Texas at Austin, Division of Materials Research, Basic Energy Sciences, Argonne National Laboratory, Oak Ridge National Laboratory, Brookhaven National Laboratory
Awards: G102163711, G107546177, G1285306620, G1286251239, G1313983767, G1525299343, G1664757510, G171842289, G1847291448, G224386356, G2287611682, G241279073, G262962599, G3075337988, G3262563802, G3281079654, G357145406, G3589692066, MRSEC: Center for Materials Innovations at Michigan, G426311843, G498139845, G513797252, G5387317844, G5535608740, G5765906131, G6482216908, G6848031779, G6918803902, G6965541988, G7463374569, G7583137537, G8286507625, G8515682721, G872144517, G969889393, G993149817
OpenAlex ID: W4416594254