Van der Waals 2D cuprate superconductors – potential device building blocks for quantum applications*

Quantum computers (QC) will provide a revolutionary tool for solving upmost complex problems that cannot be tackled efficiently by silicon-based technologies. Current Qbits, the constituents of QC, are based on conventional superconductors. These materials pose serious operating constraints as they work only close to absolute 0 K. To overcome this issue, 2-dimensional van der Waals (vdW) encapsulated high temperature superconductor (HTSC) stacks could be used as building blocks for future Qbits, thanks to recent advancements in material nanofabrication. First, a detailed understanding of their structure and electronic dynamics is required.

In this work, we present low T resonant soft X-ray studies on ultrathin Bi₂Sr₂CaCu₂O_8+y (BSCCO) vdW heterostructures - promising candidates for large scale Qbits. BSCCO crystals are characterized by two incommensurate lattice modulations (ILM), which can be exploited to witness the relation between structure and electrons in low dimensions. For the first time, we report of ILMs and structural [004] peak maps taken across the SC transition temperature (Tc ≈ 60 K). We believe this sheds light onto the electronic interplay as we find the intensity of ILMs depends on the SC state of the flake while [004] seems not to.