Switchable geometric frustration in an artificial-spin-ice-superconductor heterosystem.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Geometric frustration arises when lattice structures prevent simultaneous minimization of interaction energies, leading to degenerate states.
• High degeneracy is crucial for applications in microelectronics, including data storage, memory, and logic.
• Achieving high degeneracy, particularly in 2D systems, remains a significant challenge.

Purpose of the Study:

• To demonstrate in situ controllable geometric frustration with high degeneracy in a two-dimensional flux-quantum system.
• To explore the interaction between artificial spin ice and superconducting flux quanta for novel functionalities.
• To realize a reprogrammable flux quantum device.

Main Methods:

• Fabrication of a superconducting thin film beneath a reconfigurable artificial-spin-ice structure.
• Utilizing tunable magnetic charges in artificial spin ice to interact with superconducting flux quanta.
• Applying external magnetic fields to switch between frustrated and crystallized flux quanta states.

Main Results:

• Demonstrated controllable geometric frustration and high degeneracy in a 2D flux-quantum system.
• Observed measurable effects of different states on the superconducting critical current profile.
• Successfully realized a reprogrammable flux quanta diode by reconfiguring spin-ice magnetic states.

Conclusions:

• Tailoring energy landscapes with artificial spin ice offers a new approach to designing geometric frustration.
• This method provides a pathway to control new functionalities in diverse material systems.
• Potential applications span microelectronics, magnetic skyrmions, 2D materials, topological insulators, and soft materials.