SINE source type does not stops as per the netlist

[Debdip1007]

HI Joey

Thank you very much for your help.

I am trying to use the SINE source type with the MITLL DCSFQ circuit as the control. I use "SINE(0 315u 4g 20p 0 0 4)" as the source, where, after 4 cycles, the source should have stopped. As you can see in the figure, it does not. How can this be implemented?

Other than this, an unrelated question, is it possible to couple the external flux to a loop of 2-JJ, for example SQUID used in a tunable qubit? any other trick that can be implemented as mutual inductance between an external flux line inductor to the circuit JJ loop?

[JoeyDelp]

Hi,

I updated the sine syntax and documentation to enable this. Also added the documentation for the PWS source which can also be used to achieve something similar.

Regarding your second question, there is a good paper (https://www.researchgate.net/publication/331623179_Software_Tools_for_Flux_Trapping_and_Magnetic_Field_Analysis_in_Superconducting_Circuits) that describes how to do this.

[Debdip1007]

Thank you very much. I will update my repo in a few days.

One quick question:

What is the difference between a global .temp definition and adding a temp parameter to JJ and Resistances directly?

[JoeyDelp]

Hi,

Global temperature will apply a specific temperature to all resistive elements (JJs and resistors). Where supplying the parameter on a per device basis sets the specific device temperature in isolation. This is can be used to simulate the effect of hotspots in circuits.

[Debdip1007]

Thank you. It helped me a lot. I am looking into a noise simulation, where I want to add a noise source to the junction. I added the T_eff to the junction, but I want to know what resistance it takes into account when calculating noise current for the junction? sub-gap resistance or normal resistance or characteristic impedance of the JJ?

[JoeyDelp]

At the moment it follows the R0 (sub-gap) and stays that way since it creates the noise source at component creation stage. However that is probably not accurate enough. I'll have to update it so it follows the non-linear resistance accross switching. This might be as simple as determining 3 spectral amplitudes for the 3 resistive regions and simply using the correct one based on the JJ state throughout the simulation. I'll investigate

[Debdip1007]

Thank you. I recently came across a paper that does quantum simulation with Spice classical simulations. I think you also must have come across this paper: https://www.nature.com/articles/s41534-025-01140-8. Maybe interesting.

Thank you again for the information.