Magnetic excitations in the helical Rashba superconductor

Abstract

We investigate the magnetic excitation spectrum in the helical state of a noncentrosymmetric superconductor with inversion symmetry breaking and strong Rashba spin-orbit coupling. For this purpose, we derive the general expressions of the dynamical spin response functions under the presence of strong Rashba splitting of conduction bands, superconducting gap, and external field which lead to stabilization of Cooper pairs with finite overall momentum in a helical state. The latter is characterized by momentum space regions of paired and unpaired states with different quasiparticle dispersions. The magnetic response is determined by i) excitations within and between both paired and unpaired regions ii) anomalous coherence factors and iii) additional spin matrix elements due to helical Rashba spin texture of bands. We show that as a consequence typical correlated real space and spin space anisotropies appear in the dynamical susceptibility which would be observable as a characteristic fingerprint for a helical superconducting state in inelastic neutron scattering investigations.

arXiv comment18 pages, 5 figures

References in corpus (27)

• New directions in the pursuit of Majorana fermions in solid state systems
• Heavy fermion superconductivity and magnetic order in non-centrosymmetric $CeP{t}_{3}Si$
• Superconducting 2D system with lifted spin degeneracy: Mixed singlet-triplet state
• Topological Phases of Noncentrosymmetric Superconductors: Edge States, Majorana Fermions, and the Non-Abelian Statistics
• Fulde-Ferrell-Larkin-Ovchinnikov State in Heavy Fermion Superconductors
• Majorana Fermions and Topology in Superconductors
• Helical vortex phase in the non-centrosymmetric CePt_3Si
• The Relation of Neutron Incommensurability to Electronic Structure in High Temperature Superconductors
• Superconductivity and Magnetism in Non-centrosymmetric System: Application to CePt_3Si
• Possible pairing symmetries in SrPtAs with a local lack of inversion center
• Magnetic Properties in Non-centrosymmetric Superconductors with and without Antiferromagnetic Order
• Triplet Cooper Pair Formation by Anomalous Spin Fluctuations in Non-centrosymmetric Superconductors
• Superconductivity with Rashba Spin-Orbit Coupling and Magnetic Field
• Field-Induced Spin-Exciton Condensation in dx2-y2-wave Superconducting CeCoIn5
• Pressure effects on the unconventional superconductivity of the noncentrosymmetric LaNiC2
• The resonance peak in the electron-doped cuprate superconductors
• Conductance characteristics between a normal metal and a two-dimensional Fulde-Ferrell-Larkin-Ovchinnikov superconductor: the Fulde-Ferrell state
• Nonuniform Spin Triplet Superconductivity due to Antisymmetric Spin-Orbit Coupling in Noncentrosymmetric Superconductor CePt${}_3$Si
• Nature and symmetry of the order parameter of the noncentrosymmetric superconductor Li2Pt3B
• Gapped Dirac cones and spin texture in thin film topological insulator
• Gap function of hexagonal pnictide superconductor SrPtAs from quasiparticle interference spectrum
• Orbital-limiting and modulation induced by missing parity in non-centrosymmetric superconductors
• Fermi surface segmentation in the helical state of a Rashba superconductor
• Knight Shift in the FFLO State of a Two-Dimensional D-Wave Superconductor
• Momentum space imaging of the FFLO state
• Multi-orbital Fulde-Ferrell-Larkin-Ovchinnikov State in SrTiO_3 Heterostructures
• Dynamical magnetic response in superconductors with finite momentum pairs