The project evolves around the possibility to characterize spectroscopically the highly complex physics of high-temperature superconductors (HTSC) through the engineerization of thin flakes of cuprates like BSCCO into Van der Waals heterostructures, formed by mechanically stacking layers of 2-Dimensional (2D) materials, possessing unique properties and new functionalities not seen in standard materials, making them an irreplaceable platform for emergent electronics. The project will develop through an already stable collaboration between the THz Sapienza laboratory, directed by prof. Stefano Lupi at Sapienza University of Rome and the experimental group (Superpuddles lab) of Dr. Nicola Poccia at the Leibniz Institute of Solid State and Materials Research in Dresden. In this way, it will be possible to achieve the right equipment to meet the challenge of spectroscopically measuring VdW heterostructures in the THz/IR range, with the goal to better understand and control the strong electronic correlations of HTSCs and topological superconductors.
For d-wave superconductors at the small scales predicted to be achieved with this project, fluctuations can be a dominant aspect of the electronic transport. Hence, a twisted heterostructure can give access to the control of the relative arrangement of the nodes of the d-wave order parameter and therefore of the strong electronic correlations of the system. This knowledge will permit to design the experimental platforms on which topological superconductivity can be controlled. A d-wave order parameter has attracted a lot of attention in the studies of HTSCs because of its inherent topological characteristics and profound effect on their superconducting properties[Physica Scripta 102, 107 (2002)]. One of the distinct features of Cooper pairs in unconventional superconductors is a complex phase structure of their wavefunction encoding crucial information on the underlying correlations leading to Cooper pairing. Twist-junctions experiments aim at providing direct access to this structure by observing the phase shift due to the geometric rotation between two superconducting planes. These effects are clearly visible in Josephson plasmonic modes[Superconductor Science and Technology 13, 85¿100 (2000)][Physica C: Superconductivity 315, 1-2, 85-90 (1999)], which energies lie in the THz spectral range.