The purpose of this project is to search for novel superconducting state in materials with triangular or hexagonal lattices. Some of the materials we studied lack spatial inversion center, and thus anti-symmetric spin-orbit coupling is enhanced which can induce spin-triplet superconducting state. Others have van Hove singularity in the electronic band structure which is favored by unconventional superconducting states. We performed nuclear magnetic resonance (NMR) measurements to study the temperature, magnetic-field, and crystal axis dependence of the spin-lattice relaxation rate and Knight shift. Through these measurements, we have revealed the exotic properties of several materials.
