We explain the recently observed linear temperature dependence of the nodal Fermi velocity vF (T) in nearly optimally doped cuprates. We argue that it originates from electron-electron interaction and it is a fundamental property of an arbitrary two-dimensional (2D) Fermi liquid. We consider a spin-fermion model with input parameters extracted from the data, and we show that the T term is about 30% at 300 K, in agreement with the data. We show that the sub-leading term in vF (T) is a regular (and small) T2 correction. We also show that at a 2 kF quantum-critical point, temperature corrections to the dispersion are singular.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Aug 29 2008|