Saulius Vaitiekenas

Project title

EQUAL: Emergent Quantum Phases in Artificial Superconducting Lattices

What is your project about?

The project, which I named EQUAL, will develop programmable quantum circuits to simulate entirely new quantum phases that emerge from equal competition between different states of matter. The building blocks that I will use are superconducting junctions that can be controlled by voltages, much like transistors in modern computer chips, but operated deep in the quantum regime. By arranging these elements into artificial lattices, I will build a scalable solid-state platform for analog quantum simulation, where complex quantum behavior can be designed and explored on demand. In the long term, this approach has the potential to open new ways of studying collective quantum phenomena and inspire future technologies based on programmable quantum materials rather than conventional electronics.

How did you become interested in your particular field of research?

To me, one of the most exciting ideas in physics is the possibility of designing entirely new quantum ground states rather than only studying those found in nature. Superconducting circuits have long been considered a promising route for exploring such phenomena, but conventional all-metallic platforms were largely hardwired during fabrication and lacked the tunability needed to access more complex regimes. A major breakthrough came with the invention of semiconductor-superconductor hybrid materials in Copenhagen. I have been involved in the continued development of these materials over the years, and they have now matured into a scalable platform ready for realizing programmable quantum circuits and analog quantum simulators of novel states of matter.

What are the scientific challenges and perspectives in your project?

Many of the most interesting quantum states in nature emerge from large numbers of particles interacting collectively. The problem is that natural quantum materials are extremely difficult to control: tiny variations in disorder, geometry, or interactions can completely change their behavior. What is currently missing is a scalable and programmable platform where these properties can be tuned in a controlled way. EQUAL addresses this challenge by developing superconducting quantum circuits whose geometry and interactions can be adjusted in real time using voltages and magnetic fields. This will make it possible to deliberately create and explore new quantum states that are difficult to realize or study in naturally occurring materials.

What is your estimate of the impact, which your project may have to society in the long term?

EQUAL is a fundamental research project aimed at understanding and controlling complex quantum matter. Historically, many technological breakthroughs have followed advances in materials science and our ability to manipulate collective electronic behavior. In the long term, programmable quantum-material platforms and analog quantum simulators could help accelerate the discovery of novel materials and device concepts beyond what is possible today. Potential applications range from new approaches to information processing to advanced functional materials with properties that can be engineered rather than simply discovered in nature.

Which impact do you expect the Sapere Aude programme will have on your career as a researcher?

The Sapere Aude program allows me to establish my research group at the interface of quantum materials and analog quantum simulation. The grant allows me to develop experimental capabilities needed to realize programmable superconducting quantum simulators and position my research at the forefront of solid-state quantum simulator development. Crucially, the program enables me to educate and mentor the next generation of researchers in this rapidly developing field while strengthening my international visibility and long-term scientific leadership.