Microwave response of single crystal YBa2Cu3O7−δ films as a probe for pairing symmetry

Abstract

5T c at f = 5 GHz); (ii) the most perfect films reveal a distinct two-peak structure of the R s (T) dependence with peaks positioned at 27-30 K and 48-51 K, while such peaks are not observed in less perfect films. The peaks are mostly pronounced at moderate (e.g. 34 GHz) frequencies and gradually disappear both at higher and lower frequencies, while their temperature positions remain unchanged. These features of perfect single-crystalline YBCO films are believed to reveal their intrinsic electron properties. Taking into account the possibility of a mixed (s+id)-type pairing symmetry as well as a significant role of extended out-of-plane crystal defects (such as dislocation lines or twin planes) in Bogolyubov's quasiparticle scattering within the most perfect YBCO films, one can suggest a consistent explanation for the anomalies observed in the Z s (T) behavior.

Angular Dependence of Linear Microwave Response of Thin Superconducting Films of Yttrium–Barium Cuprate in Mixed State

“…ВТНП мають на кілька порядків нижчий поверхневий опір на відміну від звичайних металів [5,6]. Цим обумовлено більші перспективи використання цих матеріялів як бази для створення пасивних надвисокочастотних (НВЧ) пристроїв з унікальними характеристиками, наприклад, фільтрів з низькими втратами у смузі пропускання [7,8].…”