arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.04422cond-mat.mes-hallcond-mat.supr-con
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超导体中自旋相关能量输运的证据

Evidence for spin-dependent energy transport in a superconductor

M. Kuzmanović, B. Y. Wu, M. Weideneder, C. H. L. Quay, M. Aprili

摘要:

在正常金属和超导体的自旋能量激发模式中,自旋向上和向下的电子(或准粒子)携带不同的热流。这种模式只发生在自旋向上和向下的能量分布函数不相同时,最简单的是当两个自旋具有不同的有效温度时,并且可以通过注入系统的自旋极化电流来激发。虽然在正常金属中观察到了自旋相关热传输的证据,但这些测量结果是在电子分布函数上平均的。通过对介观超导体中的准粒子布居进行光谱分析,我们揭示了强非平衡态的分布函数,即非费米-狄拉克分布函数。此外,与正常金属不同,超导体中的自旋能模与有限塞曼磁场中超导能隙边缘的电荷不平衡(不同数量的空穴和电子类准粒子)有关。我们的光谱技术使我们能够观察到这种电荷不平衡,从而明确地确定自旋能量模式。我们的结果与理论符合得很好,为超导自旋热电子学奠定了基础。

英文摘要:

In the spin energy excitation mode of normal metals and superconductors, spin up and down electrons (or quasiparticles) carry different heat currents. This mode occurs only when spin up and down energy distribution functions are non-identical, most simply when the two spins have different effective temperatures, and can be excited by spin-polarised current injection into the system. While evidence for spin-dependent heat transport has been observed in a normal metal, these measurements averaged over the distribution function of the electrons. By performing spectroscopy of quasiparticle populations in a mescoscopic superconductor, we reveal distribution functions which are strongly out-of-equilibrium, i.e. non-Fermi-Dirac. In addition, unlike in normal metals, the spin energy mode in superconductors is associated with a charge imbalance (different numbers of hole- and electron-like quasiparticles) at the superconducting gap edge, in finite Zeeman magnetic fields. Our spectroscopic technique allows us to observe this charge imbalance and thus unambiguously identify the spin energy mode. Our results agree well with theory and contribute to laying the foundation for spin caloritronics with superconductors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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