Self-trapping phase diagram for the strongly correlated extended Holstein-Hubbard model in two-dimensions
The two-dimensional extended Holstein-Hubbard model is investigated in the strong correlation regime to study the nature of self-trapping transition and the polaron phase diagram in the absence of superconductivity. Using a series of canonical transformations followed by zero-phonon averaging the ex...
Saved in:
Published in | The European physical journal. B, Condensed matter physics Vol. 87; no. 7 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.07.2014
Springer |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The two-dimensional extended Holstein-Hubbard model is investigated in the strong correlation regime to study the nature of self-trapping transition and the polaron phase diagram in the absence of superconductivity. Using a series of canonical transformations followed by zero-phonon averaging the extended Holstein-Hubbard model is converted into an effective extended Hubbard model which is subsequently transformed into an effective
t
-
J
model in the strong correlation limit. This effective
t
-
J
model is finally solved using the mean-field Hartree-Fock approximation to show that the self-trapping transition is continuous in the anti-adiabatic limit while it is discontinuous in the adiabatic limit. The phase diagrams for the localization-delocalization transition, namely the phase line and the phase surface separating the small polaron and large polaron states are also shown. |
---|---|
ISSN: | 1434-6028 1434-6036 |
DOI: | 10.1140/epjb/e2014-50146-9 |