含顺磁杂质超导体中的束缚态

本文利用广义正则变换和自洽场方法,讨论了单个杂质对超导体的影响。证明在磁性杂质附近,可能形成一个束缚态的元激发,其能量位于能隙之中。求出了能级和波函数的解析表达式,并计算了束缚能级所引起的附加电磁吸收。讨论了与此有关的隧道和高频吸收实验。此外,还讨论了非磁性杂质对连续谱元激发的影响及杂质附近能隙的变化。

BOUND STATE IN SUPERCONDUCTORS WITH PARAMAGNETIC IMPURITIES

A generalized canonical transformation and a SCF method have been used to investigate the influence of isolated impurity atoms on the properties of superconductors. It has been found that a bound state of excitation exists around a paramagnetic impurity with its energy level in the energy gap. An analytical expression has been obtained for the corresponding wave function. The effect of electromagnetic absorption due to the bound state should appear as a precursory peak. The possible experimental verifications of the bound state through tunnelling effect and infrared absorption are discussed.Futhermore, the excitations of continuous spectra around a nonmagnetic impurity and the spatial variation of the energy gap parameter have been considered.