Systems, methods and apparatus for measuring magnetic fields

摘要

SQUIDs may detect local magnetic fields. SQUIDS of varying sizes, and hence sensitivities may detect different magnitudes of magnetic fields. SQUIDs may be oriented to detect magnetic fields in a variety of orientations, for example along an orthogonal reference frame of a chip or wafer. The SQUIDS may be formed or carried on the same chip or wafer as a superconducting processor (e.g., a superconducting quantum processor). Measurement of magnetic fields may permit compensation, for example allowing tuning of a compensation field via a compensation coil and/or a heater to warm select portions of a system. A SQIF may be implemented as a SQUID employing an unconventional grating structure. Successful fabrication of an operable SQIF may be facilitated by incorporating multiple Josephson junctions in series in each arm of the unconventional grating structure.

主权项

1. A system for measuring magnetic fields in a local environment of a device, the system comprising:
a first superconducting quantum interference device (“SQUID”) comprising a closed superconducting current path formed by a planar loop of material that is superconducting below a critical temperature, wherein the closed superconducting current path is interrupted by at least one Josephson junction; wherein the first SQUID is integrated into the device such that the first SQUID is carried on a predominately planar surface of the device and the first SQUID is responsive to magnetic fields in the local environment of the device that are orthogonal to the predominately planar surface; a second SQUID comprising a closed superconducting current path formed by a planar loop of material that is superconducting below a critical temperature, wherein the closed superconducting current path of the second SQUID is interrupted by at least one Josephson junction and wherein the second SQUID is integrated into the device such that the second SQUID is carried on the predominately planar surface of the device; and wherein the closed superconducting current path of the first SQUID encloses a first area and the closed superconducting current path of the second SQUID encloses a second area, and wherein the second area is larger than the first area.