Phason and amplitudon in the charge-density-wave phase of one-dimensional charge stripes in La(2-x)Sr(x)CuO4

Phys Rev Lett. 2006 Apr 7;96(13):137003. doi: 10.1103/PhysRevLett.96.137003. Epub 2006 Apr 6.

Abstract

The present systematic Raman scattering experiments reveal the phason and amplitudon of the charge density wave (CDW) mode in the charge stripes of La(2-x)Sr(x)CuO4. Only about 15% of the electronic density of states condenses into the CDW state. The symmetries of the CDW modes change by the rotation of the stripes at the insulator-metal transition. The energy of the phason is finite at 0.06 < or = x < or = 0.1 and zero at x = 0.035 and 0.115 < or = x < or = 0.135, which suggests that the CDW is commensurate at 0.06 < or = x < or = 0.1 and incommensurate otherwise. The zero-energy phason seems to reduce T(c) at x = 1/8.