Band structure of the jahn-teller polaron from quantum monte carlo
A path-integral representation for the Jahn-Teller polaron (JTP) is constructed. It leads to a perturbation series that can be summed exactly by the diagrammatic quantum Monte Carlo technique. The ground-state energy, effective mass, spectrum, and density of states of the three-dimensional JTP are calculated with no systematic errors. The band structure of JTP is found to be similar to that of the Holstein polaron. The mass of JTP increases exponentially with the coupling constant. At small phonon frequencies, the spectrum of JTP is flat at large momenta, which leads to a strongly distorted density of states with a massive peak at the top of the band.
Kornilovitch
PE
Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BZ, United Kingdom.