Alterpiezoresponse in Two-Dimensional Lieb-Lattice Altermagnets

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid State Chemistry

Background:

• Altermagnetism, characterized by alternating spin structures in reciprocal space, is an emerging field of significant scientific interest.
• Transition-metal chalcogenides M2WS4, based on Lieb lattices, represent a novel class of altermagnetic materials.
• Understanding the interplay between crystal symmetry and magnetic/electric responses is crucial for novel material functionalities.

Purpose of the Study:

• To predict and investigate novel real-space alternative piezomagnetic and piezoelectric responses in M2WS4 altermagnets.
• To elucidate the role of unique crystal-spin symmetry (S4T) in dictating distinct magnetic and electric behaviors under stress.
• To explore the potential of these materials for independent control of electric and magnetic properties.

Main Methods:

• Theoretical prediction of piezomagnetic and piezoelectric effects in M2WS4 compounds.
• Analysis of crystal-spin symmetry (S4T) and its influence on material responses.
• Investigation of responses under different stress conditions (axial vs. diagonal).

Main Results:

• Axial stress induces a giant piezomagnetic response (1-2 orders of magnitude larger than conventional materials) due to S4T symmetry.
• Residual C2 symmetry suppresses the piezoelectric effect under axial stress.
• Diagonal stress leads to a significant piezoelectric response by creating electric dipole moment imbalance, while inhibiting piezomagnetism due to in-plane mirror symmetry.

Conclusions:

• M2WS4 altermagnets exhibit an alternative piezoresponse, enabling independent control of electric and magnetic properties.
• This unique property opens new avenues for developing high-fidelity multifunctional memory and sensor applications.
• The findings highlight the potential of altermagnetic materials in next-generation electronic devices.