NMR studies of coexistence of superconductivity and CDW in LaPt₂Si₂

We carried out ¹³⁹La-, ²⁹Si- and ¹⁹⁵Pt-NMR measurements of LaPt₂Si₂ which shows coexistence of a superconducting state and a charge density wave (CDW) state. Slight gradual decreasing ∼0.006% are observed in Knight shifts of ¹³⁹La and ²⁹Si-line C from 200K to 5K. The decreasing are much less than the previous ¹⁹⁵Pt-NMR spectra PeakD's shifts reported in T. Kubo et al, so the decreasing can be expected following ¹⁹⁵Pt-Knight shift decreasing. LaPt₂Si₂ has two types of Pt-sites: Pt(1)2a(Wycoff position) and Pt(2)2c. By carrying out single crystalline ¹⁹⁵Pt-NMR, the site assignments of ¹⁹⁵Pt-NMR spectra to each respective Pt sites are succeeded for both H||a and ||c. Associating for 1/T₁T results for polycrystalline powder reported by T. Kubo et al, Pt(1)-site may contributes to the CDW order below T∗. It is necessary to measure the temperature dependences of line1's 1/T₁T by using single crystalline LaPt₂Si₂.