saipavanc
commented
1 week ago We did think about such a possibility, and we added this functionality a while back, though this is not documented as we weren't sure as to how many would be interested in it. In the Circuit module, you can define higher order Josephson junctions in the following way:
import scqubits as scq
circ_input = """
branches:
- [JJ2, 0, 1, 20, 2, 3]
- [L, 0, 1, 0.4]
"""
circ = scq.Circuit(circ_input, from_file=False)
circ$$ H = 12.0 Q{1}^{2} + \left(0.2 (2πΦ{1})^{2} + 0.2 θ{1}^{2} - 3.0 \cos{\left(2.0 θ{1} \right)} - 20.0 \cos{\left(θ{1} \right)} + 0.4 (2πΦ{1}) θ_{1}\right) $$
For defining the order the format is - [JJ<order>, node_1, node_2, EJ_1, EJ_2, ..., EJ_{order}, ECJ], following the syntax as usual to define a branch. The rest of the functionality should work as expected. Please let us know if you will experience any bugs.
edumur
petergthatsme
Dear all,
We work with multi-harmonic Josephson element, see https://arxiv.org/abs/2405.14695 for instance. One way of describing them is to replace the usual $$E\mathrm{J} = I\mathrm{c} \cos \left( \varphi \right)$$ By $$E\mathrm{J} = I\mathrm{c1} \cos \left( \varphi\right) + I\mathrm{c2} \cos \left( 2 \varphi\right) + I\mathrm{c3} \cos \left( 3 \varphi\right) + ... $$
I have no idea how to add such functionality in scqubit which has a quite complicated code for me ^^' . Could you guide to realize such improvement?
Thanks!