Determination of Niobium Cavity Magnetic Field Screening via a Dispersively Hybridized Magnonic Sensor

Abstract

A method for determining the internal DC magnetic field inside a superconducting cavity is presented. The method relies on the relationship between magnetic field and frequency of the Kittel mode of a ferrimagnetic sphere, hybridised in the dispersive regime of the superconducting cavity. Results were used to experimentally determine the level of screening a superconducting Nb cavity provides as it changes from perfect diamagnetism to no screening. Two cavity geometries were tested, a cylinder and single post re-entrant cavity. Both demonstrated a consistent value of field that enters the cavity, expected to be the superheating critical field. Hysteresis in the screened field during ramp up and ramp down of the external magnetic field due to trapped vortices was also observed. Some abnormal behaviour was observed in the cylindrical cavity in the form of plateaus in the internal field above the first critical field, and we discuss the potential origin of this behaviour. The measurement approach would be a useful diagnostic for axion dark matter searches, which plan on using superconducting materials but need to know precisely the internal magnetic field.

arXiv comment8 pages, 6 figures

References in corpus (22)

• Hybridizing ferromagnetic magnons and microwave photons in the quantum limit
• High Cooperativity Cavity QED with Magnons at Microwave Frequencies
• Bidirectional conversion between microwave and light via ferromagnetic magnons
• Resolving magnon number states in quantum magnonics
• Ultra-High Cooperativity Interactions between Magnons and Resonant Photons in a YIG sphere
• Quantum magnonics: magnon meets superconducting qubit
• Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mG
• Broadening Frequency Range of a Ferromagnetic Axion Haloscope with Strongly Coupled Cavity-Magnon Polaritons
• Efficient expulsion of magnetic flux in superconducting RF cavities for high $Q_0$ applications
• Study of the cavity-magnon-polariton transmission line shape
• High Q-factor Sapphire Whispering Gallery Mode Microwave Resonator at Single Photon Energies and milli-Kelvin Temperatures
• Operation of a ferromagnetic axion haloscope at $m_a=58\mu$eV
• Theoretical estimates of maximum fields in superconducting resonant radio frequency cavities: Stability theory, disorder, and laminates
• Role of surface defects and material inhomogeneities for vortex nucleation in superconductors within time-dependent Ginzburg-Landau theory in 2 and 3 dimensions
• Cavity Magnon Polaritons with Lithium Ferrite and 3D Microwave Resonators at milli-Kelvin Temperatures
• Cavity design for high-frequency axion dark matter detectors
• Flux expulsion in niobium superconducting radio-frequency cavities of different purity and essential contributions to the flux sensitivity
• Spin-Photon Interaction in a Cavity with Time-Reversal Symmetry Breaking
• Axion production and detection with superconducting RF cavities
• Universal behavior of the IMS domain formation in superconducting niobium
• Single Crystal Sapphire at milli-Kelvin Temperatures: Observation of Electromagnetically Induced Thermal Bistability in High Q-factor Whispering Gallery Modes
• Record High-Gradient SRF Beam Acceleration at Fermilab