Doping dependence of Meissner effect in triangular-lattice superconductors

TL;DR

This paper investigates how doping levels affect the Meissner effect in triangular-lattice superconductors, revealing exponential temperature dependence and a dome-shaped doping dependence of superfluid density within a kinetic-energy-driven pairing framework.

Contribution

It introduces a detailed analysis of doping and temperature effects on the Meissner effect in triangular-lattice superconductors using a kinetic-energy-driven mechanism, highlighting the influence of geometric frustration.

Findings

Magnetic-field-penetration depth shows exponential temperature dependence.

Superfluid density peaks around critical doping, then decreases with further doping.

Doping dependence of superconducting transition temperature exhibits a dome shape.

Abstract

In the spin-excitation-mediated pairing mechanism for superconductivity, the geometric frustration effects not only the spin configuration but also the superconducting-state properties. Within the framework of the kinetic-energy-driven superconducting mechanism, the doping and temperature dependence of the Meissner effect in triangular-lattice superconductors is investigated. It is shown that the magnetic-field-penetration depth exhibits an exponential temperature dependence due to the absence of the d-wave gap nodes at the Fermi surface. However, in analogy to the dome-like shape of the doping dependence of the superconducting transition temperature, the superfluid density increases with increasing doping in the lower doped regime, and reaches a maximum around the critical doping, then decreases in the higher doped regime.