Spin-dynamics in the S= 1/2 trimer chain compound Na2Cu3Ge4O12

Spin-trimer chain systems are of current interest due to unconventional properties arising from the strong quantum fluctuations and topology, such as, quantum phenomenon of magnetization plateau. The presence or absence of plateaus is strongly related to the relative strength and sign of the intratrimer and intertrimer exchange interactions. The compound Na2Cu3Ge4O12 is a model spin-1/2 AFM trimer chain system with a non-collinear ordered ground state below TN = 2.25 K. Our recent inelastic neutron scattering measurements on Na2Cu3Ge4O12 using the MERLIN spectrometer down to 2.2 K reveal three discrete energy excitation modes at ~ 2.6, 18.5 and 30 meV, with an additional weak low energy dispersive band below 2.6 meV suggesting a couple trimer model. Here, we propose additional detailed low-energy measurements using LET spectrometer which are essential to determine the spin Hamiltonian.