Periodic Reporting for period 1 - DESIQM (Designer superconductivity in interacting quantum metamaterials)
Período documentado: 2022-01-01 hasta 2023-12-31
Transitioning to renewable energy sources is crucial for combating climate change. However, these sources are often located in remote locations, far away from the bustling urban centres with the highest energy demands. Meanwhile, the mass adoption of electric vehicles is necessary for reaching emission targets but exacerbates urban energy demand, creating a bottleneck for clean power. Consequently, achieving a sustainable future presents a hidden challenge: how can we efficiently transport clean electricity over long distances?
Conventional power grids lose significant energy during long-distance transmission (8-15%) and rely on bulky copper wires requiring considerable space. Superconducting wires, with zero electrical resistivity, could overcome this limitation. A superconducting power grid would completely eliminate the energy lost during transmission and require much less space compared to traditional copper grids (80% more compact). However, conventional superconductors require extremely low temperatures achievable only with expensive liquid helium cooling, making them impractical for widespread use.
Some materials exhibit unconventional superconductivity at higher temperatures, allowing them to operate with cheaper liquid nitrogen. However, their operating temperatures remain too low for large-scale power grid integration. The overall objective of the project is to advance the viability of unconventional superconductors by creating “designer superconductors”.
The key characteristic of unconventional superconductors is that their electrons interact strongly with one another. But this behaviour is hard to anticipate, and unconventional superconductors are often discovered more by chance than by design. The DESIQM project explored a new design-first approach for the bottom-up fabrication of custom unconventional superconductors with strong electron interactions, called “interacting quantum metamaterials”.
These quantum metamaterials are constructed by moving individual atoms or molecules with a scanning tunnelling microscope to create a pattern that modifies surface electron behaviour. The project proposed a quantum metamaterial on the surface of a topological Kondo insulator, which already hosts strongly interacting surface electrons—the key ingredient of unconventional superconductors. However, finding atoms to effectively manipulate these electrons was a challenge.
The project's major conclusion is the identification of “Kondo holes” – a class of atoms ideally suited for fabricating quantum metamaterials on topological Kondo insulators. This discovery paves the way for developing efficient, high-temperature designer superconductors that could revolutionize clean energy transmission for a sustainable future.
Conventional power grids lose significant energy during long-distance transmission (8-15%) and rely on bulky copper wires requiring considerable space. Superconducting wires, with zero electrical resistivity, could overcome this limitation. A superconducting power grid would completely eliminate the energy lost during transmission and require much less space compared to traditional copper grids (80% more compact). However, conventional superconductors require extremely low temperatures achievable only with expensive liquid helium cooling, making them impractical for widespread use.
Some materials exhibit unconventional superconductivity at higher temperatures, allowing them to operate with cheaper liquid nitrogen. However, their operating temperatures remain too low for large-scale power grid integration. The overall objective of the project is to advance the viability of unconventional superconductors by creating “designer superconductors”.
The key characteristic of unconventional superconductors is that their electrons interact strongly with one another. But this behaviour is hard to anticipate, and unconventional superconductors are often discovered more by chance than by design. The DESIQM project explored a new design-first approach for the bottom-up fabrication of custom unconventional superconductors with strong electron interactions, called “interacting quantum metamaterials”.
These quantum metamaterials are constructed by moving individual atoms or molecules with a scanning tunnelling microscope to create a pattern that modifies surface electron behaviour. The project proposed a quantum metamaterial on the surface of a topological Kondo insulator, which already hosts strongly interacting surface electrons—the key ingredient of unconventional superconductors. However, finding atoms to effectively manipulate these electrons was a challenge.
The project's major conclusion is the identification of “Kondo holes” – a class of atoms ideally suited for fabricating quantum metamaterials on topological Kondo insulators. This discovery paves the way for developing efficient, high-temperature designer superconductors that could revolutionize clean energy transmission for a sustainable future.
The research carried out during the action focussed on two areas. The primary focus was constructing a specialized platform for creating designer superconductors. This platform comprised two key components: a cutting-edge, fourth-generation scanning tunnelling microscope (STM) and a custom-built cryostat capable of reaching ultra-low temperatures. Unfortunately, unforeseen COVID-19 restrictions disrupted the construction timeline, causing delays in acquiring essential equipment and materials. Despite this setback, the high-precision STM was successfully completed after a year of project time. This microscope operates at the atomic scale, allowing users to precisely arrange and manipulate materials with incredible detail—a crucial capability for constructing designer superconductors. While the cryostat faced further delays, it was ultimately finalized by project completion. With both next-generation instruments now in place, the future development of designer superconductors is primed for significant progress.
The second research area focused on identifying suitable building blocks for designer superconductors. Due to the delays in constructing the STM, the project leveraged existing data on promising materials called “topological Kondo insulators,” focusing on naturally occurring defects within these materials. The project successfully identified a scattering mechanism that allows a broad class of these defects to interact effectively with surface electrons in topological Kondo insulators. This interaction is crucial, as it allows these defects to function as the fundamental building blocks for constructing quantum metamaterials. Notably, the discovery extends to readily available atoms that can be introduced through a controlled process or may even occur naturally on the surface of these materials. This finding holds immense promise for the future. The vast array of potentially suitable defects paves the way for the development of custom electronic phases with tailored properties, a key objective of the project.
The project disseminated its research findings to a broad audience. Key findings were published in a top peer-reviewed scientific journal and presented at leading international conferences. Outreach activities included a YouTube talk and a press release, while public lab tours offered a first-hand look at the project's cutting-edge research tools.
The second research area focused on identifying suitable building blocks for designer superconductors. Due to the delays in constructing the STM, the project leveraged existing data on promising materials called “topological Kondo insulators,” focusing on naturally occurring defects within these materials. The project successfully identified a scattering mechanism that allows a broad class of these defects to interact effectively with surface electrons in topological Kondo insulators. This interaction is crucial, as it allows these defects to function as the fundamental building blocks for constructing quantum metamaterials. Notably, the discovery extends to readily available atoms that can be introduced through a controlled process or may even occur naturally on the surface of these materials. This finding holds immense promise for the future. The vast array of potentially suitable defects paves the way for the development of custom electronic phases with tailored properties, a key objective of the project.
The project disseminated its research findings to a broad audience. Key findings were published in a top peer-reviewed scientific journal and presented at leading international conferences. Outreach activities included a YouTube talk and a press release, while public lab tours offered a first-hand look at the project's cutting-edge research tools.
In addition to the construction of a fourth-generation STM and cryostat, the project made a significant breakthrough in the characterization of materials at the atomic level. The project pioneered a new technique called Kondo Resonance Spectroscopy (KRS), a powerful tool for measuring tiny variations in electric charge within a material. This capability is important because many promising electronic materials are affected by slight variations in electric charge, but existing techniques often struggle to measure them, especially in metallic materials. KRS overcomes this challenge by offering a high-resolution view of the nanoscale electrical charge within special materials called Kondo lattices. This advancement is expected to lead to the development of even more powerful tools that act as general-purpose atomic-scale charge sensors. These sensors will be tiny detectors that can measure the electrical state of complex materials, including those with unconventional superconductivity or exotic properties like Majorana zero modes.