Microwave measurements of the high magnetic field vortex motion pinning parameters in Nb$_3$Sn

TL;DR

This study investigates the microwave response of Nb$_3$Sn in high magnetic fields up to 12 T, measuring vortex motion parameters using a dielectric resonator at 15 GHz, revealing its potential for high-frequency applications.

Contribution

First microwave measurements of vortex motion parameters in Nb$_3$Sn under strong magnetic fields, expanding understanding of its high-frequency properties.

Findings

Determined vortex pinning constant, depinning frequency, and flux flow resistivity in Nb$_3$Sn.

Showed Nb$_3$Sn's suitability for high-frequency applications in strong magnetic fields.

Compared Nb$_3$Sn's microwave response with other superconductors.

Abstract

The high frequency vortex motion in Nb$_3$Sn was analyzed in this work up to 12 T. We used a dielectric loaded resonator tuned at 15 GHz to evaluate the surface impedance $Z$ of a Nb$_3$Sn bulk sample (24.8 at.\%Sn). From the field induced variation of $Z$, the high frequency vortex parameters (the pinning constant $k_p$, the depinning frequency $\nu_p$ and the flux flow resistivity $\rho_{ff}$) were obtained over a large temperature and field range; their field and temperature dependence were analyzed. Comparison with other superconducting materials shows that high frequency applications in strong magnetic fields are also feasible with Nb$_3$Sn. In the present work, we report the first measurements about the microwave response in Nb$_3$Sn in strong magnetic fields.