  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.
