Josephson tunnel junctions consist of two superconductors with a thin insulating barrier in-between and, for decades, these circuit elements have been described with a simple sinusoidal model.

However, as the researchers demonstrate, this "standard model" fails to fully describe the Josephson junctions that are used to build quantum bits. Instead, an extended model including higher harmonics is required to describe the tunneling current between the two superconductors. The principle can also be found in the field of music. When the string of an instrument is struck, the fundamental frequency is overlaid by several harmonic overtones.

I was looking into challenges facing quantum stability and it seems noise and vibration effect the qubits and along the way I stumbled upon this new idea.