Charge-Spin Separation and the Spectral Properties of Luttinger Liquids

Kai-Hua Yang, Bin Chen, Yunfeng Sun +1 more

Krzysztof Byczuk, Józef Spałek

Pierluigi Falco, Vieri Mastropietro

Alex Levchenko

Johannes Voit

We compute the spectral function \ensuremath{\rho}(q,\ensuremath{\omega}) of the one-dimensional Luttinger model. Charge-spin separation gives spectral weight at frequencies between the charge and spin-fluctuation dispersions while spectral weight above ${\mathit{v}}_{\mathrm{\ensuremath{\rho}}}$q and below -${\mathit{v}}_{\mathrm{\ensuremath{\rho}}}$q is related to the anomalous dimensions of the fermion operators. The generalization of these results to many-particle correlations is discussed as well as the possibilities for their experimental verification in quasi-one-dimensional conductors.

Johannes Voit

We compute the spectral function rho (q, omega ) of the one-dimensional Luttinger model. We discuss the distinct influences of charge-spin separation and of the anomalous dimensions of the fermion operators and their evolution with correlation strength. Charge-spin separation shows up in finite spectral weight at frequencies between v sigma q and v rho q, where v sigma and v rho are the velocities of spin and charge fluctuations, while spectral weight above v rho q and below -v rho q is generated by the hybridization of the Fermi surface at +or-k F by interactions. There are non-universal power-law singularities at these special frequencies. We discuss the consistency of recent photoemission experiments on low-dimensional conductors with a Luttinger-liquid picture, which then would suggest very strong long-range interactions. It is pointed out that many-particle correlation functions in principle exhibit similar singularities, but they probe different and complementary aspects of the Fermi-surface interactions.