Amplitude Mode Of Charge Density Wave In Ttf[Ni(Dmit)(2)](2) Observed By Electronic Raman Scattering

We measured the optical signature of charge density waves (CDWs) in the multiband conductor TTF[Ni(dmit)(2)](2) by electronic Raman scattering. At low energies, a hump develops below 60 K. This hump is associated to the amplitude mode of the CDW with an energy around 9 meV. Raman symmetry-resolved measurements show that the CDW amplitude mode is anisotropic and that the CDW can be associated to the band nesting of Ni(dmit)(2) chains.