High temperature superconducting devices for quantum technology

2D van der Waals materials-based heterostructures have led to new devices for fundamental science and applications. Superconducting Josephson devices based on 2D materials offer unique opportunities to engineer new functionality for quantum technology. After a longish pedagogical introduction, I will present results from our studies using the van der Waals, layered superconductor Bi2Sr2CaCu2O8+δ with a transition temperature of ~85K. First, we have realized a bolometer using nanowires of Bi2Sr2CaCu2O8+δ  [1] with prospects of single photon detector at ~50K. Second, twisted van der Waals heterostructures based on high Tc superconductor Bi2Sr2CaCu2O8+δ lead to the realization of a high-temperature Josephson diode [2] for the first time. Non-reciprocal devices in the superconducting state, such as Josephson diodes, are of interest for fundamental physics and technology.

References:

[1] " Nanowire bolometer using a 2D high-temperature superconductor" Sanat Ghosh et al. Nanotechnology 34 015304 (2023).  
[2] "High-temperature Josephson diode," Sanat Ghosh et al. Nature Materials https://www.nature.com/articles/s41563-024-01804-4  (2024).