Skyrmion generation from irreversible fission of stripes in chiral multilayer films

Abstract

Competing interactions produce finite-size textures in myriad condensed matter systems, typically forming elongated stripe or round bubble domains. Transitions between stripe and bubble phases, driven by field or temperature, are expected to be reversible in nature. Here we report on the distinct character of the analogous transition for nanoscale spin textures in chiral Co/Pt-based multilayer films, known to host Néel skyrmions, using microscopy, magnetometry, and micromagnetic simulations. Upon increasing field, individual stripes fission into multiple skyrmions, and this transition exhibits a macroscopic signature of irreversibility. Crucially, upon field reversal, the skyrmions do not fuse back into stripes, with many skyrmions retaining their morphology down to zero field. Both the macroscopic irreversibility and the microscopic zero-field skyrmion density are governed by the thermodynamic material parameter determining chiral domain stability. These results establish the thermodynamic and microscopic framework underlying ambient skyrmion generation and stability in chiral multilayer films and provide immediate directions for their functionalization in devices.

v1 with supplementary materials

References in corpus (4)

• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmion at room temperature
• Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
• (Ir-)Reversibility and thermal equilibrium in magnetic domain pattern formation in ultra-thin ferromagnetic films

Cited by in corpus (7)

• All-Electrical Skyrmionic Bits in a Chiral Magnetic Tunnel Junction
• Unveiling the emergent traits of chiral spin textures in magnetic multilayers
• Thermal evolution of skyrmion formation mechanism in chiral multilayer films
• Nano-engineering the evolution of skyrmion crystal in synthetic antiferromagnets
• Tailoring Zero-Field Magnetic Skyrmions in Chiral Multilayers by a Duet of Interlayer Exchange Couplings
• Controlling magnetic skyrmion nucleation with Ga+ ion irradiation
• Zero Field Antiferromagnetically Coupled Skyrmions and their Field-Driven Uncoupling in Composite Chiral Multilayers