Nonlinear Microwave Response of MgB2 Thin Films

Published

July 11, 2003

Author(s)

James Booth, S. Y. Lee, Kenneth Leong, J. H. Lee, J. Lim, H. N. Lee, B. Oh, S. H. Moon

Abstract

Thin films of the newly discovered superconductor MgB₂ show promise for a number of different electronic applications. In order to evaluate the suitability of this new material for communication applications at microwave frequencies, we have measured both the linear and nonlinear microwave response of ex-situ MgB₂ thin films on sapphire substrates patterned into coplanar waveguide transmission lines. Linear measurements yield the characteristic impedance of our CPW transmission lines, as well as the complex conductivity of the MgB₂ film. The nonlinear response of transmission lines on the same film was measured by harmonic generation techniques. Assuming that the measured nonlinear response is due to kinetic inductance effects, we are able to directly determine the relevant pair-breaking current density in our MgB₂ thin films by combining results from our linear and nonlinear measurements. Because the resulting pair-breaking current density is a material property independent of sample geometry, we can make quantitative comparisons of the nonlinear response of MgB₂ thin films and YBCO thin films at comparable reduced temperatures. We find that the pair-breaking current density in MgB₂ thin films rivals that in YBCO for sufficiently low reduced temperatures.

Proceedings Title

Extended Abstracts, 2003 Intl. Superconductive Electronics Conf. (ISEC)

Conference Dates

July 7-11, 2003

Conference Location

Sydney, 1, AS

Pub Type

Conferences

Keywords

magnesium diboride, nonlinear microwave, superconducting electronics

Citation

Booth, J. , Lee, S. , Leong, K. , Lee, J. , Lim, J. , Lee, H. , Oh, B. and Moon, S. (2003), Nonlinear Microwave Response of MgB₂ Thin Films, Extended Abstracts, 2003 Intl. Superconductive Electronics Conf. (ISEC), Sydney, 1, AS (Accessed October 13, 2025)