Work

Pairing gaps near ferromagnetic quantum critical points

Year: 2015

Type: article

Abstract: We address the quantum-critical behavior of two-dimensional itinerant ferromagnetic systems described by spin-fermion models in which fermions interact with close-to-critical bosonic modes. We consider Heisenberg ferromagnets, Ising ferromagnets, and the Ising nematic transition. Mean-field theory close to the quantum critical point predicts a superconducting gap with spin-triplet symmetry for the ferromagnetic systems and a singlet gap for the nematic scenario. Studying fluctuations in this ordered phase using a nonlinear sigma model, we find that these fluctuations are not suppressed by any small parameter. As a result, we find that a superconducting quasi-long-range order is still possible in the Ising-like models but long-range order is destroyed in Heisenberg ferromagnets.

Source: Physical Review B

DOI: 10.1103/physrevb.91.064507

Authors: M. Einenkel, H. Meier, C. Pépin, K. B. Efetov

Institutions: National University of Science and Technology, Ruhr University Bochum, Yale University, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Institut de Physique Théorique

Language: English

Topic: Physics of Superconductivity and Magnetism

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Deutsche Forschungsgemeinschaft, Agence Nationale de la Recherche, Ministry of Education and Science of the Russian Federation

Awards: G1113938619, G6072216627, UNconventional Electronic States and Charge Orders versus Superconductivity