Superconducting current control system

A method for controlling an amplitude of a control current provided to a superconducting circuit device, the method comprising:

• coupling the superconducting circuit device to a current control element via an inductive coupler, the current control element comprising a superconducting quantum interference device (SQUID) array comprising a plurality of radio frequency (RF) SQUIDs, each of the SQUIDs being inductively coupled to a bias line;
• providing an input current through the current control element, such that the current control element is configured as a tunable inductive path for the input current, the input current corresponding to at least a portion of a load current, the load current being provided through a load inductor of the inductive coupler to inductively provide the control current from a control inductor associated with the inductive coupler;
• and
• providing a bias current on the bias line to control an amplitude of the input current, the amplitude of the input current controlling an amplitude of the load current through the load inductor based on an amplitude of the bias current.

A superconducting current control system comprising:

• an inductive coupler comprising a load inductor and a control inductor, the inductive coupler being configured to inductively provide a control current from the control inductor to a superconducting circuit device based on a load current being provided through the load inductor as a first portion of an input current that is received at an input of the superconducting current control system, a second portion of the input current being provided parallel with the first portion;
• and
• a current control element comprising a first superconducting quantum interference device (SQUID) array and a second SQUID array arranged in parallel between a first terminal and a second terminal, each of the first and second SQUID arrays comprising a plurality of RF SQUIDs, each of the RF SQUIDs being inductively coupled to a bias line configured to conduct a bias current, the current control element being configured as a tunable inductive path for an input current corresponding to at least a portion of the load current, the bias line being configured to conduct a bias current to control an amplitude of the input current, the amplitude of the input current being configured to control an amplitude of the load current through the load inductor based on an amplitude of the bias current, the current control element being coupled to the inductive coupler via at least one of the first and second terminals to control an amplitude of the load current through the load inductor based on an amplitude of the bias current, the control current having an amplitude that is based on the amplitude of the load current.