Abstract
Abstract
The isotope effect in the superconducting transition temperature is anomalous if the isotope coefficient α < 0 or α > 1/2. In this work, we show that such anomalous behaviors can naturally arise within the Bardeen–Cooper–Schrieffer framework if both phonon and non-phonon modes coexist. Different from the case of the standard Eliashberg theory (with only phonon) in which α ⩽ 1/2, the isotope coefficient can now take arbitrary values in the simultaneous presence of phonon and the other non-phonon mode. In particular, most strikingly, a pair-breaking phonon can give rise to large isotope coefficient α > 1/2 if the unconventional superconductivity is mediated by the lower frequency non-phonon boson mode. Based on our studies, implications on several families of superconductors are discussed.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Subject
General Physics and Astronomy
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献