SPICE Workshop on Quantum Matter for Quantum Technologies, May 21st - May 23rd 2024
Mandar Deshmukh
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. I will present results from two classes of materials. First, proximitized graphene-based Josephson junctions lead to a quantum noise-limited parametric amplifier with performance comparable to best discrete amplifiers in this class [1]. Gate tunability of the center frequency of the amplifier, rather than flux, offers key advantages. An extension of graphene Josephson architecture to make state-of-the-art bolometers leveraging graphene's low specific heat, and I will present initial results. 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. Such Josephson diodes offer an opportunity to engineer the current phase relationship and the resulting inductive response for many applications close to liquid nitrogen temperature.
[1] "Quantum-noise-limited microwave amplification using a grapheneJosephson junction" Joydip Sarkar et al. , Nature Nanotechnology 17, 1147 (2022). [2] "High-temperature Josephson diode," Sanat Ghosh et al. Nature Materials (2024) https://www.nature.com/articles/s41563-024-01804-4