Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2021

Идентификатор DOI: 10.1088/1361-6668/abff6f

Ключевые слова: unconventional superconductors, iron pnictides, iron chalcogenides, impurity scattering, penetration depth

Аннотация: One of the features of the unconventional s(+/-) state in iron-based superconductors is possibility to transform to the s(++) state with the increase of the nonmagnetic disorder. Detection of such a transition would prove the existence of the s(+/-) state. Here we study the temperature dependence of the London magnetic penetration depth within the two-band model for the s(+/-) and s(++) superconductors. By solving Eliashberg equations accounting for the spin-fluctuation mediated pairing and nonmagnetic impurities in the T-matrix approximation, we have derived a set of specific signatures of the s(+/-) -> s(++) transition: (1) sharp change in the behavior of the penetration depth lambda(L) as a function of the impurity scattering rate at low temperatures; (2) before the transition, the slope of Delta lambda(L) (T) = lambda(L)(T) - lambda(L)(0) increases as a function of temperature, and after the transition this value decreases; (3) the sharp jump in the inverse square of the penetration depth as a function of the impurity scattering rate, lambda(-2)(L) (Gamma(a)), at the transition; (4) change from the single-gap behavior in the vicinity of the transition to the two-gap behavior upon increase of the impurity scattering rate in the superfluid density rho(s) (T).

Журнал: SUPERCONDUCTOR SCIENCE & TECHNOLOGY

Выпуск журнала: Vol. 34, Is. 7

Номера страниц: 75008

ISSN журнала: 09532048

Место издания: BRISTOL

Издатель: IOP PUBLISHING LTD

• Shestakov V.A. (RAS, Fed Res Ctr KSC SB, Kirensky Inst Phys, Krasnoyarsk 660036, Russia)
• Korshunov M.M. (RAS, Fed Res Ctr KSC SB, Kirensky Inst Phys, Krasnoyarsk 660036, Russia; Siberian Fed Univ, Krasnoyarsk 660041, Russia)
• Togushova Yu N. (Siberian Fed Univ, Krasnoyarsk 660041, Russia)
• Dolgov O.V (RAS, PN Lebedev Phys Inst, Moscow 119991, Russia; Donostia Int Phys Ctr, San Sebastian 20018, Spain)

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