Controllable Emergent Spatial Spin Modulation in Sr_{2}IrO_{4} by In Situ Shear Strain

Area of Science:

• Condensed Matter Physics
• Materials Science
• Magnetism

Background:

• Anisotropic interactions in magnetic materials can exhibit competing ferromagnetic and antiferromagnetic properties along different crystallographic axes.
• Understanding these interactions is key to discovering novel magnetic states.

Purpose of the Study:

• To investigate the emergence of new exotic magnetic states through the competition of anisotropic interactions.
• To demonstrate a general route for achieving tunable spatial spin modulation in low-dimensional magnets.

Main Methods:

• Applying in situ shear strain to quasi-two-dimensional antiferromagnetic Sr2IrO4 single crystals.
• Utilizing X-ray diffraction or similar techniques to observe structural and magnetic phase transitions.
• Analyzing the interplay between inherent quadratic and strain-activated fourth-order anisotropic interactions.

Main Results:

• Observed the emergence of a continuously tunable 12-layer spatial spin modulation.
• Identified this modulation as a translation-symmetry-breaking phase.
• Demonstrated that a strain-activated anisotropic interaction competes with the inherent quadratic anisotropic interaction.

Conclusions:

• The competition of orthogonal irreducible representation anisotropic interactions is a viable route to novel magnetic states.
• Strain engineering provides a controllable method to manipulate magnetic properties in low-dimensional materials.
• This mechanism of competing anisotropy offers a distinct approach compared to conventional ferromagnetic, antiferromagnetic, and Dzyaloshinskii-Moriya interactions.