Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons

Details Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons

2004-04-07

arxiv.org/abs/cond-mat/0404154v6

Phys. Rev. B 71, 205113 (2005)

Physics

Condensed Matter

Strongly Correlated Electrons

Published version; 18 pages, 20 figures

Scientific paper

10.1103/PhysRevB.71.205113

Using a multistep renormalization group method, we study the low-temperature phases of the interacting one-dimensional (1D) electron gas coupled to phonons. We obtain analytic expressions for the weak-coupling quantum phase boundaries of the 1D extended Holstein-Hubbard model and the 1D extended Peierls-Hubbard model for general band-filling and phonon frequency. Away from half-filling, the phase diagrams are characterized by a delicate competition between spin density wave, charge density wave, and superconducting orders. We study the dependence of the ground state on the electron-phonon (el-ph) and electron-electron (el-el) coupling strengths, the screening length, electron bandwidth, phonon frequency, doping, and type of phonon. Unlike the case in Fermi liquids, in 1D the el-ph coupling is strongly renormalized, often to stronger values. Even when the bare phonon-induced attraction is weak compared to the bare el-el repulsion, a small amount of retardation can cause the renormalized el-ph interaction to dominate the problem. We find cases in which a repulsive el-el interaction enhances the superconducting susceptibility in the presence of a retarded el-ph interaction. The spin gap and superconducting susceptibility are found to be strongly dependent on the deviation from half-filling (doping). In some cases, the superconducting susceptibility varies nonmonotonically with doping and exhibits a maximum at a particular doping. For a quasi-1D array of weakly coupled, fluctuating 1D chains, the superconducting transition temperature T_c also exhibits a maximum as a function of doping. The effect of changing the ion mass (isotope effect) on T_c is found to be largest near half-filling and to decrease rapidly with doping.

Affiliated with

Also associated with

No associations

Rating

Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-243367