Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons
| dc.creator | Bindloss, Ian P. | |
| dc.date | 2004-04-07 | |
| dc.date | 2005-05-29 | |
| dc.date.accessioned | 2026-07-07T02:57:29Z | |
| dc.date.available | 2026-07-07T02:57:29Z | |
| dc.description | 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. | |
| dc.description | Published version; 18 pages, 20 figures | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0404154 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0404154 | |
| dc.identifier | Phys. Rev. B 71, 205113 (2005) | |
| dc.identifier | doi:10.1103/PhysRevB.71.205113 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/23689 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.subject | Superconductivity | |
| dc.title | Phase diagram and isotope effects of the quasi-one-dimensional electron gas coupled to phonons | |
| dc.type | text |