Systems and methods for applying flux to a quantum-coherent superconducting circuit
AssigneeNorthrop Grumman Systems Corporation
InventorsQuentin P. HERR, Ofer NAAMAN, Anna Y. HERR
Life of this patent
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Abstract
Systems and methods are provided for applying flux to a quantum-coherent superconducting circuit. In one example, a system includes a long-Josephson junction (LJJ), an inductive loop coupled to the LJJ and inductively coupled to the quantum-coherent superconducting circuit, and a single flux quantum (SFQ) controller configured to apply a SFQ pulse to a first end of the LJJ that propagates the SFQ pulse to a second end of the LJJ, while also applying a flux quantum to the inductive loop resulting in a first value of control flux being applied to the quantum-coherent superconducting circuit.
Claims20
A system for applying flux to a quantum-coherent superconducting circuit, the system comprising:
- a long-Josephson junction (LJJ);
- an inductive loop coupled to the LJJ and inductively coupled to the quantum-coherent superconducting circuit;
- and
- a single flux quantum (SFQ) controller configured to apply a single flux quantum (SFQ) pulse to a first end of the LJJ that propagates the positive SFQ pulse to a second end of the LJJ, while also applying a flux quantum to the inductive loop resulting in a first value of control flux being applied to the quantum-coherent superconducting circuit.
A system for applying flux to a quantum-coherent superconducting circuit, the system comprising:
- a long-Josephson junction (LJJ) implemented as a Josephson junction array in a long-Josephson-junction limit arrangement;
- an inductive loop coupled to the LJJ at a midpoint of the LJJ and inductively coupled to the quantum-coherent superconducting circuit;
- a DC source inductively coupled to the inductive loop to provide a DC flux bias to establish a half of flux quantum that establishes a bi-stable persistent current in the inductive loop that is initially in a first direction;
- and
- a single flux quantum (SFQ) controller configured to apply a positive single flux quantum (SFQ) pulse to a first end of the LJJ that propagates the positive SFQ pulse to a matched load at a second end of the LJJ, while also applying a flux quantum to the inductive loop resulting in a first value of control flux being applied to the quantum-coherent superconducting circuit.
A method for applying flux to a quantum-coherent superconducting circuit, the method comprising:
- providing an inductive loop coupled to a long-Josephson junction (LJJ) at a midpoint of the LJJ and inductively coupled to the quantum-coherent superconducting circuit;
- applying a DC flux bias to the inductive loop to establish a half of flux quantum that establishes a bi-stable persistent current in the inductive loop that is initially in a first direction;
- and
- applying a positive single flux quantum (SFQ) pulse to a first end of the LJJ that propagates the positive SFQ pulse to a matched load at a second end of the LJJ, while also applying a flux quantum to the inductive loop resulting in a first value of control flux applied to the quantum-coherent superconducting circuit.
Dependencies are inferred from the claim text.