Quantum phenomena in unconventional superconductor junctions

库珀对的对称性一般可分为偶频自旋-单重偶宇称（ESE）态、偶频自旋-三重偶宇称（ETO）态、奇频自旋-三重偶宇称（OTE）态和奇频自旋-单重偶宇称（OSO）态。在格林函数形式主义的框架下，我们提出了扩散正常金属（DN）和非常规超导体之间结的接近效应的一般理论。在超导体中考虑了以上四种可能的对称性：ESE态、ETO态、OTE态和OSO态。对于上述四种情况中的每一种，都确定了在由于杂质散射的DN中只有偶宇称s波对可能的情况下，DN中诱导对振幅的对称性和谱性质。结果表明，在一个DN中的对振幅分别属于ESE、OTE、OTE和ESE配对态。在奇频配对态存在的情况下，得到的态密度有一个零能量峰。附加在ETO纵波超导体上的DN中OTE态的产生与Sr2RuO4结中新型接近效应的相关性特别令人感兴趣。为了解决这个问题，我们现在正在用FIG技术制备Sr2RuO4的结。我们进一步证明，超导体中的自旋-单线偶宇称（自旋-三重偶宇称）偶势在界面附近诱导出具有自旋-单线偶宇称（自旋-三重偶宇称）的奇频配对分量。由于界面处各向异性偶势的符号变化，在中隙安德烈夫谐振态存在时，感应奇频分量的大小增强。讨论了准二维自旋三重态超导体Sr2RuO4的电子拉曼光谱。利用Keldysh Green函数理论计算了拉曼光谱，并考虑了序参量集合模式。我们考虑了杂质散射的影响。杂质散射对准粒子激发对拉曼光谱的贡献产生了相当大的影响，同时引起了集体模共振峰的展宽和峰位的移动。少

Symmetry of the Cooper pair can be generally classified into even-frequency spin-singlet even-parity (ESE) state, even-frequency spin-triplet odd-parity (ETO) state, odd-frequency spin-triplet even-parity (OTE) state and odd-frequency spin-singlet odd-parity (OSO) state. We present a general theory of the proximity effect in junctions between diffusive normal metals (DN) and unconventional superconductors in the framework of the Green's function formalism. Above four possible symmetry classes in a superconductor are considered: ESE, ETO, OTE and OSO state. For each of the above four cases symmetry and spectral properties of the induced pair amplitude in the DN are determined where only the even-parity s-wave pairing is possible due to the impurity scattering in DN. It is shown that the pair amplitude in a DN belongs respectively to an ESE, OTE, OTE and ESE pairing state In the presence of the Odd-frequency pairing state, the resulting density of state has a zero energy peak. The genera … More tion of the OTE state in the DN attached to the ETO p-wave superconductor is of particular interest in the relevance to the novel proximity effect in Sr2RuO4 junctions. In order to resolve this point, we are now preparing the junction made from Sr2RuO4 Using FIG technique. We further demonstrate that, quite generally, the spin-singlet even-parity (spin-triplet odd-parity) pair potential in a superconductor induces the odd-frequency pairing component with spin-singlet odd-parity (spin-triplet even-parity) near interfaces. The magnitude of the induced odd-frequency component is enhanced in the presence of the midgap Andreev resonant state due to the sign change of the anisotropic pair potential at the interface. We discussed the electronic Raman spectra of the quasi-two-dimensional spin-triplet superconductor Sr2RuO4. The Raman spectra are calculated using the Keldysh Green's function theory taking into account the order parameter collective mode. We take into account the effect of impurity scattering. The impurity scattering gives rise to considerable modification of the contribution from the quasiparticle excitations to the Raman spectra and simultaneously to the broadening of the collectivemode resonance peak and the shift of the peak position. Less