Freestanding Flexible Vortex Tubes Integrated With Ferroelectric Transistor

Polar topologies hold great potential in information storage. So far, thin films with polar topological structure are predominantly constrained by the substrate on which they are grown. Such substrate-stabilized polar topologies limit their integration into memory devices, and consequently, their physical behaviors in data memory remain unclear. Here, we show a ferroelectric field-effect transistor (Fe-FET) memory device, which is based on large-scale freestanding pure polar vortex tube arrays. In situ heating demonstrates that vortex tube arrays in freestanding superlattices undergo a more directly reversible phase transition, evolving from vortex tubes to single domains and ultimately to the disappearance of ferroelectricity. The flexible vortex tubes, which are obtained by removing the sacrificial layers, could bend at a 90° without breaking, demonstrating the nature of robustness. The Fe-FET exhibits a wide and stable clockwise hysteresis loop, spanning a voltage range of -60 to 60 V and temperatures from room temperature to 450 K. Due to the stable and robust ferroelectric vortex dipole moment arrays, the Fe-FET achieves a memory retention time of 3600 s and an endurance of 10⁴ cycles.