Josephson wide band multiplexer-demultiplexer circuit

A superconducting circuit comprising:

• a first port and a plurality of second ports;
• a plurality of filter poles, each filter pole comprising an inductor and a capacitor connected in parallel, between the first port and a second port in the plurality of second ports, wherein the plurality of filter poles comprises greater than 2 filter poles;
• an admittance inverter comprising at least one of a coupling capacitor, a coupling inductor, and a Josephson junction, the admittance inverter linking two successive filter poles together,
• wherein at least one filter pole of the plurality of filter poles together with the admittance inverter define a current branch (IB), and
• wherein a first configuration of the plurality of filter poles and a second configuration of the associated admittance inverters define a plurality of current branches so that:
• the superconducting circuit is adapted such that an input electrical current input through the first port is routed to a selected one of the plurality of the plurality of second ports by an application of a first set of magnetic flux biases, wherein the single magnetic flux bias feeds and is connected to each of multiple ones of the plurality of filter poles for a defined stage;
• and
• the superconducting circuit is adapted such that an input electrical current input through any one of the plurality of second ports is routed as an output electrical current output through the first port by the application of a second set of magnetic flux biases, wherein the single magnetic flux bias feeds and is connected to each of multiple ones of the plurality of filter poles for the defined stage.