Identifying fractionalized magnetic excitations in the triangular spin-liquid candidate Na2BaCo(PO4)2

The experimental identification of quantum spin liquids (QSL) in real materials has been one of the challenging and fundamental goals in condensed matter physics. The newly discovered QSL candidate material Na2BaCo(PO4)2 forms triangular layers of Co2+ (jeff = 1/2) ions stacked along c-axis. Our preliminary experimental results give no hint for magnetic and structural phase transitions down to 50 mK. In addition, the large magnetic entropy points towards the presence of abundant low-lying magnetic excitations at low temperatures. Putting these together, Na2BaCo(PO4)2 is an attracting platform to explore the QSL in the triangular lattice. The proposed inelastic neutron scattering studies will critically test a QSL scenario by probing low-lying magnetic excitations as a function of temperature and magnetic field and thus determining spin-spin correlations.