Orbital-Controlled Superconductivity in f-Electron Systems

TL;DR

This paper introduces a concept of orbital-controlled superconductivity in f-electron systems, demonstrating how orbital degrees of freedom influence phase transitions in CeMIn5 compounds through microscopic modeling.

Contribution

It presents a multiorbital model analyzed via fluctuation exchange approximation, revealing orbital-dependent phase changes without Fermi-surface alterations.

Findings

Ground state varies among paramagnetic, antiferromagnetic, and superconducting phases.

Orbital components near Fermi energy determine phase behavior.

Explains diverse low-temperature properties of CeMIn5.

Abstract

We propose a concept of superconductivity controlled by orbital degree of freedom taking CeMIn5 (M= Co, Rh, and Ir) as typical examples. A microscopic multiorbital model for CeMIn5 is analyzed by fluctuation exchange approximation. Even though the Fermi-surface structure is unchanged, the ground state is found to change significantly among paramagnetic, antiferromagnetic, and d-wave superconducting phases, depending on the dominant orbital component in the band near the Fermi energy. We show that our picture naturally explains the different low-temperature properties of CeMIn5 by carefully analyzing the crystalline electric field states.