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

التفاصيل البيبلوغرافية
العنوان: Determination of Niobium Cavity Magnetic Field Screening via a Dispersively Hybridized Magnonic Sensor
المؤلفون: Flower, Graeme, McAllister, Benjamin, Goryachev, Maxim, Tobar, Michael
المصدر: Applied Physics Letters, 117(16):162401 (2020)
سنة النشر: 2020
المجموعة: Condensed Matter
Quantum Physics
مصطلحات موضوعية: Condensed Matter - Superconductivity, Condensed Matter - Strongly Correlated Electrons, Quantum Physics
الوصف: 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.
Comment: 8 pages, 6 figures
نوع الوثيقة: Working Paper
DOI: 10.1063/5.0023547
URL الوصول: http://arxiv.org/abs/2008.05073
رقم الأكسشن: edsarx.2008.05073
قاعدة البيانات: arXiv