On the determination of the quasiparticle scattering rate in unconventional superconductors by microwave surface impedance

• Дата: 2013
• Автори: Cherpak, N.T., Barannik, A.A., Prozorov, R., Tanatar, M., Velichko, A.V.
• Формат: Стаття
• Мова: English
• Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2013
• Назва видання: Физика низких температур
• Теми: Краткие сообщения
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/118928
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: On the determination of the quasiparticle scattering rate in unconventional superconductors by microwave surface impedance / N.T. Cherpak, A.A. Barannik, R. Prozorov, M. Tanatar, A.V. Velichko // Физика низких температур. — 2013. — Т. 39, № 12. — С. 1423–1425. — Бібліогр.: 25 назв. — англ.

As found from numerous microwave experiments on the unconventional Fe-based superconductors, the temperature dependence of the quasiparticle scattering rate t⁻¹ cannot be accurately described within the framework of standard Drude module in the popular approximation of wt << 1, where w is the signal frequency. To account for the discrepancy, we have extended the classical Drude model for the case of arbitrary values of wt, and obtained the expression for t⁻¹ as a function of experimentally measurable quantities, namely the real and imaginary parts of the microwave surface impedance. We then show the temperature dependence of t⁻¹ in supercon-ducting Ba(Fe₁–xCox)₂As₂ single crystal pnictide derived from the Ka-band surface impedance measurements within the framework of the modified expression. The measurements indicate the extent to which assumption of wt << 1 gives results different from those obtained without this restriction, i.e., incorrect results.