During the first two years of the project, activities on all four design principles—symmetry, emergence, engineered platforms, and parameter tuning—have started, with the aim to discover new correlation-driven gapless topological phases, establish design principles for such phases, reveal new signatures of these phases, and assess their potential for quantum devices.
At focus are heavy fermion compounds, as versatile platforms for the investigation of strong correlation phenomena. The compound Ce3Bi4Pd3, recently discovered by the PI and her collaborators as the first material exhibiting a correlation-driven gapless topological phase, serves as the starting point for the project.
The workflow in the project is that once a promising compound is identified (via the above design principles), the first step is the synthesis of pure bulk single crystals, to ensure that the measured properties are intrinsic. Various growth techniques are employed, as well as various structural and analytical measurements to characterize the crystals. In addition, molecular beam epitaxy is used to grow selected compounds as thin films. Then, various physical property measurements are performed, including new ones devised within the project, at need under multiple extreme conditions of temperature, magnetic field, and pressure. Experiments at large facilities (neutrons, muons, x-rays, high fields) complement the laboratory experiments. Another important aspect of the project is close collaboration with different teams of theorists, using complementary approaches to guide the material discovery.
Progress has been made on most project aspects. New equipment was delivered and installed, and new synthesis and measurement techniques were developed. Some promising compounds were identified using the proposed design principles. Some of them were grown and investigated. Several interesting and, in part, unexpected and puzzling observations were already made.
