Disclosed herein is a non-reciprocal circuit element that includes a dielectric substrate having upper and lower surfaces, a magnetic rotator mounted on the dielectric substrate, and a permanent magnet that applies a magnetic field to the magnetic rotator. The dielectric substrate has a connection pattern formed on the upper surface thereof and connected to the magnetic rotator, a terminal electrode formed on the lower surface thereof and connected to the connection pattern, and a capacitor pattern formed on the upper surface, lower surface or inside the dielectric substrate.

An integrated qubit readout circuit is presented, which includes a superconducting parametric amplifier, a circuit board arranged to mount the superconducting parametric amplifier, a circulator mounted on the circuit board and connected to the superconducting parametric amplifier, wherein the circulator comprises a termination port electrically connected to a termination resistor arranged to terminate a pump tone received by the superconducting parametric amplifier, and wherein the termination resistor is mounted on the circuit board.

An integrated qubit readout circuit is presented, which includes a superconducting parametric amplifier, a circuit board arranged to mount the superconducting parametric amplifier, a circulator mounted on the circuit board and connected to the superconducting parametric amplifier, wherein the circulator comprises a termination port electrically connected to a termination resistor arranged to terminate a pump tone received by the superconducting parametric amplifier, and wherein the termination resistor is mounted on the circuit board.

Disclosed herein is a non-reciprocal circuit element that includes a magnetic rotator, a permanent magnet for applying a magnetic field to the magnetic rotator, a lower yoke, and an upper yoke fixed to the lower yoke and housing therein the magnetic rotator and the permanent magnet. The upper yoke includes a top plate part that covers the magnetic rotator and the permanent magnet from an upper side, and first and second side plate parts that face each other and cover the magnetic rotator and the permanent magnet from a side. The first and second side plate parts have first and second plate spring parts that sandwich the permanent magnet and bias it.

Disclosed herein is a non-reciprocal circuit element that includes a magnetic rotator, a permanent magnet for applying a magnetic field to the magnetic rotator, a lower yoke, and an upper yoke fixed to the lower yoke and housing therein the magnetic rotator and the permanent magnet. The upper yoke includes a top plate part that covers the magnetic rotator and the permanent magnet from an upper side, and first and second side plate parts that face each other and cover the magnetic rotator and the permanent magnet from a side. The first and second side plate parts have first and second plate spring parts that sandwich the permanent magnet and bias it.

Disclosed herein is a non-reciprocal circuit element that includes a substrate having lower and upper surfaces, a magnetic metal layer provided on the lower surface of the substrate, a magnetic rotator provided on the upper surface of the substrate, and a permanent magnet for applying a magnetic field to the magnetic rotator. The magnetic metal layer includes a lower yoke provided at a position overlapping the magnetic rotator in a plan view and a plurality of terminal electrodes connected to the magnetic rotator.

Disclosed herein is a non-reciprocal circuit element that includes a substrate having lower and upper surfaces, a magnetic metal layer provided on the lower surface of the substrate, a magnetic rotator provided on the upper surface of the substrate, and a permanent magnet for applying a magnetic field to the magnetic rotator. The magnetic metal layer includes a lower yoke provided at a position overlapping the magnetic rotator in a plan view and a plurality of terminal electrodes connected to the magnetic rotator.

A circulator includes a central circuit having a first superconducting island, a second superconducting island, a third superconducting island, and a central island, each in electrical communication with each other via a plurality of Josephson junctions.

A circulator includes a central circuit having a first superconducting island, a second superconducting island, a third superconducting island, and a central island, each in electrical communication with each other via a plurality of Josephson junctions.

Integration of self-biased magnetic circulators with microwave devices is disclosed herein. In microwave and other high-frequency radio frequency (RF) applications, a magnetic circulator can be implemented with a smaller permanent magnet. Aspects disclosed herein include a process flow for producing a self-biased circulator in an integrated circuit chip. In this regard, a magnetic circulator junction can be fabricated on an active layer of a semiconductor wafer. A deep pocket or cavity is formed in an insulating substrate under the active layer. This cavity is then filled with a ferromagnetic material such that the circulator junction is self-biased within the integrated circuit chip, eliminating the need for an external magnet. The self-biased circulator provides high isolation between ports in a smaller integrated circuit.