Analytical Result on Electronic States around a Vortex Core in a Noncentrosymmetric Superconductor

Abstract

We analytically study electronic bound states around a single vortex core in a noncentrosymmetric superconductor such as CePt3Si without mirror symmetry about the ab plane. Considering a mixed spin-singlet-triplet Cooper pairing model, we obtain a formula about the local density of states (LDOS) around a vortex core in any direction of the magnetic field. The LDOS under a magnetic field perpendicular to the c axis is quite different from that of typical s-wave or d-wave superconductors. From the ellipticity of the spatial pattern of the LDOS around a vortex core, one can experimentally estimate the pairing symmetry of CePt3Si, such as the position of the gap nodes and the ratio of the singlet component to the triplet component in the order parameter.

Superconductivity in non-centrosymmetric materials

“…An especially interesting aspect is the behavior in magnetic fields when spin-orbit coupling gives rise unusual response to Zeeman coupling. Other aspects such as the vortex physics [34], surface states [35] and Josephson effect [36] may contain novel intriguing features. It is conceivable that artificially structured superconductors (multi-layered systems) may be created which by design show some of these novel behaviors.…”

Superconducting gap function in the organic superconductor (TMTSF)2ClO4with anion ordering; First-principles calculations and quasiclassical analysis for ang

“…Furthermore, it is emphasized that KPA can calculate the density of states even in complicated Fermi surfaces without any heavy numerical computations. So far, we have actually examined various unconventional superconductors with the use of KPA [15][16][17]31,32 .…”

Superconductivity and Magnetism in Non-centrosymmetric System: Application to CePt3Si

“…The mixing of spin singlet and spin triplet pairings is induced by the antisymmetric spin-orbit coupling (ASOC). 17) Recent theoretical studies led to the discussion of interesting properties of a non-centrosymmetric superconductor, such as the magnetelectric effect, [18][19][20][21] anisotropic spin susceptibility 17,[21][22][23][24][25][26][27][28][29] accompanied by the anomalous paramagnetic depairing effect, 29) anomalous coherence factor in NMR 1=T 1 T, 20,30) anisotropic SC gap, 28,[30][31][32][33] helical SC phase, 29,[34][35][36][37][38][39] FuldeFerrel-Larkin-Ovchinnikov (FFLO) state at zero magnetic field, 40) various impurity effects, [41][42][43][44] vortex state, 45,46) and tunneling/Josephson effect. [47][48][49][50][51][52] Non-centrosymmetric heavy fermion superconductors, i.e., CePt 3 Si, UIr, CeRhSi 3 , CeIrSi 3 , and CeCoGe 3 , are of particular interests because non-s-wave superconductivity is realized owing to strong electron correlation effects and magnetism ha...…”