| dc.contributor.advisor | Kopietz, Peter Prof. Dr. | de |
| dc.contributor.author | Bartosch, Lorenz | de |
| dc.date.accessioned | 2013-01-22T15:54:14Z | de |
| dc.date.available | 2013-01-30T23:50:59Z | de |
| dc.date.issued | 2000-08-29 | de |
| dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-000D-F185-A | de |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-3498 | |
| dc.format.mimetype | ContentType:application/pdf Size:990 | de |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | de |
| dc.title | Singularities and Pseudogaps in the Density of States of the Fluctuating Gap Model | de |
| dc.type | doctoralThesis | de |
| dc.contributor.referee | Kopietz, Peter Prof. Dr. | de |
| dc.date.examination | 2000-06-21 | de |
| dc.subject.dnb | 29 Physik, Astronomie | de |
| dc.subject.gok | RV | de |
| dc.description.abstracteng | We review the one-dimensional fluctuating
gap model (FGM) which describes non-interacting fermions subject to
a static random backscattering potential. The FGM applies to the
low-energy behavior of quasi one-dimensional Peierls and spin
systems and has recently also been used to explain the pseudogap
phenomenon in high-$T_c$ superconductors. After an elementary
introduction to the FGM, we develop methods which allow for a
simultaneous calculation of the density of states (DOS) and the
inverse localization length. First, we recover all known results in
the limits of zero and infinite correlation length of the random
potential. Then, we attack the problem of finite correlation
lengths. While a complex order parameter, which describes
incommensurate Peierls chains, leads to a suppression of the DOS,
i.e. a pseudogap, the DOS exhibits a singularity at the Fermi
energy if the order parameter is real and therefore refers to a
commensurate system. We confirm these results by calculating the
DOS and the inverse localization length for finite correlation
lengths and Gaussian statistics of the backscattering potential
with unprecedented accuracy numerically. Finally, we consider the
case of classical phase fluctuations which apply to low
temperatures where amplitude fluctuations are frozen out. In this
physically important regime which is also governed by finite
correlation lengths, we present analytic results for the DOS, the
inverse localization length, the specific heat, and the Pauli
susceptibility. | de |
| dc.contributor.coReferee | Schönhammer, Kurt Prof. Dr. | de |
| dc.subject.topic | mathematics and natural science | de |
| dc.subject.eng | fluctuating gap model | de |
| dc.subject.eng | Peierls chains | de |
| dc.subject.eng | pseudogap | de |
| dc.subject.eng | singularities | de |
| dc.subject.bk | 33.10 | de |
| dc.subject.bk | 33.60 | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-webdoc-851-1 | de |
| dc.identifier.purl | webdoc-851 | de |
| dc.identifier.ppn | 320962687 | |