Improved superconductivity with periodic nano/micro patterning
Superconductors are materials that can conduct electricity without resistance. Their superconducting behaviour is observed at and below very low temperatures (Transition Temperature, TC), generally under cryogenic conditions; all economically relevant superconductors have to be cooled down far below the boiling point of liquid nitrogen. Conventional superconductors as NbTi, NbSn3, Nb, and Al are used in sensing applications and magnets for nuclear magnetic imaging instruments. However, the costs of cryogenic cooling make most technologies based on superconductors very expensive and hinders a more widespread application.
Researchers at Leiden University have invented a method to improve the superconductivity in these and other materials.
This technology is based on a new approach to engineer/improve superconducting materials: deliberate alterations of the mesoscale structure of the material are realized by using nano and microfabrication techniques, resulting into a controlled modification of the phononic and electronic structure of thin films. This allows the coupling of the electrons with the phonon modes at higher temperatures, with the consequent formation of Cooper pairs and the onset of supercurrents. The physics model that underlies this technology shows how such periodic structures have to be designed to best improve superconductivity.
Figure 1: Possible fabrication methods and realizations. a. Modern nanofabrication tools allow to make periodic patterns. b. Different shapes are possible. c. Different layers of (insulating) materials on top of the thin films have different effects. d. Stacking allows for 3D materials. e,f. Smaller patterning are possible using Moire engineering or single atom manipulation.
Applications can be found in all markets where superconductors are currently used, including:
- Superconducting wires in MRI and NMR instruments.
- Sensors, including for astronomy and superconducting quantum interference devices (SQUID).
Further, future sensing and quantum computing/information applications are envisioned.
While the fabrication technology is well established and the underlying physics model has passed through peer-review scrutiny, its experimental validation and optimisation are ongoing at the moment of writing.The technology is available for licensing (for commercial use or for evaluation and/or co-development)
Luris reference numberINV-008.046
Patent protection has been applied for.
Data available on request
More information can be found on a recent publication (available at arxiv.org/abs/1704.06805)