Abstract
EuAl4, a known skyrmion magnet, represents a class of materials that show complex electronic behaviors involving long-wavelength charge density wave (CDW). Here we realize direct real-space imaging of the concomitant periodic lattice distortion (PLD) with picometer precision in EuAl4. Simultaneous imaging of microstructure, polarization, and interatomic distance is made possible using cryogenic four-dimensional scanning transmitting electron microscopy (cryo-4DSTEM). With this approach, we determined that the PLD in EuAl4 incorporates two out-of-phase atomic displacement modes on the Eu and Al sublattices. The PLD introduces periodic local symmetry fluctuations from the average symmetry of the bulk EuAl4 crystal. This critical local structural insight helps understanding of charge-spin-lattice couplings behind the intertwined quantum order in EuAl4. Our results also demonstrate cryo-4DSTEM as an indispensable approach for probing CDW and related quantum materials at low temperatures.
| Original language | English |
|---|---|
| Article number | 104414 |
| Journal | Physical Review Materials |
| Volume | 8 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2024 |
Funding
Microscopy was supported by a DOE-BES Early Career project FWP #ERKCZ55 (H.N.). Technique development was performed under DOE, Basic Energy Sciences, Materials Sciences, and Engineering Division (M.C.) and microscopy performed at the ORNL’s Center for Nanophase Materials Sciences (CNMS), which is a DOE Office of Science User Facility. W.R.M., H.M., and A.F.M. were supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. J.M.Z. was supported by the U.S. DOE, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-SC0024064.