Model for Vortex-Core Tunneling Spectroscopy of Chiralp-Wave Superconductors via Odd-Frequency Pairing States

Abstract

The local density of states is studied theoretically in terms of the odd-frequency (odd-omega) Cooper pairing induced around a vortex core. We find that a zero energy peak in the density of states at the vortex center is robust against nonmagnetic impurities in a chiral p-wave superconductor owing to an odd-omega s-wave pair amplitude. We suggest how to discriminate a spin-triplet pairing symmetry and spatial chiral-domain structure by scanning tunneling spectroscopy via odd-omega pair amplitudes inside vortex cores.

Site-selective NMR for odd-frequency Cooper pairs around vortex in chiralp-wave superconductors

“…As for the chiral p-wave superconductor, previous theories suggest that the temperature T dependence of T −1 1 is different between p + and p − states at the vortex center [12][13][14]. This chirality dependence is caused by the interaction between the chirality and vorticity, depending on whether the chirality L z (= ± 1) is parallel or antiparallel to the vorticity W (=1) in the vortex state of chiral p-wave superconductors [15][16][17][18].…”

“…Majorana fermions give rise to anomalous electric states such as Majorana zero mode and non-Abelian * ktanaka@mp.okayama-u.ac.jp † ichioka@cc.okayama-u.ac.jp statistics of the vortices [20]. In addition, the vortex state of chiral p-wave superconductors also induces odd-frequency Cooper pairs [18,22,23]. In particular, the odd-frequency s-wave Cooper pair in the vortex state of chiral p-wave superconductors is related to the Majorana fermion [23].…”

Possible Odd-Frequency Superconductivity in Strong-Coupling Electron–Phonon Systems

“…[2][3][4] Since then, the OF pairing has been discussed in a wide variety of theoretical models, e.g., the Kondo lattice, [5][6][7][8][9] the square-lattice 10) and the triangularlattice [11][12][13] Hubbard, and t-J 14) models. A universal feature of superconductivity so far stimulates to discuss the OF pairing in connection with experimental reality in the heavyfermion systems, 15,16) superconducting junctions, [17][18][19][20][21][22][23][24][25][26][27][28][29][30] vortex core, 31,32) proximity effect of superfluid 3 He 33) and the cold atoms. 34) Aside from the intensive studies, the homogenous state of the OF pairing has struggled against the fundamental difficulties such as the thermodynamic instability 7,35,36) and the unphysical Meissner effect.…”

Emergence of Non-Axisymmetric Vortex in Strong-Coupling Chiral p-Wave Superconductor

“…This state is topologically non-trivial and attracts much attention in these days. Within the vortices of this superconductor, reflected in the topology of this system, there is a zero-energy bound state, which is expected to be very robust against not-so-strong impurities [13,14,15,16,17,18,19,20,21]. Recently, the relationship between this robustness and the odd-frequency pairing also has been discussed [17,21,22].…”