相关论文: Spectral signatures of Holstein polarons
We performed an extensive numerical analysis of the Holstein model. Combining variational Lanczos diagonalisation, density matrix renormalisation group, kernel polynomial expansion, and cluster perturbation theory techniques we solved for…
The two-dimensional Holstein model is studied by means of direct Lanczos diagonalization preserving the full dynamics and quantum nature of phonons. We present numerical exact results for the single-particle spectral function, the polaronic…
In this paper the polaron problem for the Holstein model is studied in the weak coupling limit. We use second order perturbation theory to construct renormalized electron and phonons. Eigenstates of the Hamiltonian are labelled and the…
The polaron features of the one-dimensional Holstein Molecular Crystal Model are investigated by improving a variational method introduced recently and based on a linear superposition of Bloch states that describe large and small polaron…
Polarons are quasiparticles formed as a result of lattice distortions induced by charge carriers. The single-electron Holstein model captures the fundamentals of single polaron physics. We examine the power of the exponential ansatz for the…
We investigate the low-energy properties of the Holstein polaron through calculation of the q-dependent phonon spectral function using an improved exact-diagonalization technique, defined over a variational Hilbert space. We perform a…
The properties of the polaron and bipolaron are explored in the 1D Jahn-Teller model with dynamical quantum phonons. The ground-state properties of the polaron and bipolaron are computed using a recently developed variational method.…
A new variational technique is developed to investigate the polaronic features of the Holstein Molecular Crystal Model. It is based on a linear superposition of Bloch states that describe large and small polaron wave functions. It is shown…
We describe a variational method to solve the Holstein model for an electron coupled to dynamical, quantum phonons on an infinite lattice. The variational space can be systematically expanded to achieve high accuracy with modest…
We study the Holstein polaron in transverse magnetic field using non-perturbational methods. At strong fields and large coupling, we show that the polaron has a Hofstadter spectrum, however very distorted and of lower symmetry than that of…
The one-electron spectral function of the Holstein-Hubbard bipolaron in one dimension is studied using cluster perturbation theory together with the Lanczos method. In contrast to other approaches, this allows one to calculate the spectrum…
We perform an unitary transformation for the symmetric phonon mode of the Holstein molecular crystal hamiltonian. We show how to compute the electronic spectral functions by exact numerical diagonalisation of an effective hamiltonian fully…
We calculate the spectral properties of the one-dimensional Holstein and breathing polarons using the self-consistent Born approximation. The Holstein model electron-phonon coupling is momentum independent while the breathing coupling…
The phonon spectral function of the one-dimensional Holstein model is obtained within weak and strong-coupling approximations based on analytical self-energy calculations. The characteristic excitations found in the limit of small…
The spectral weight functions and the optical conductivity of the Holstein model are studied on a one-dimensional six-site lattice with periodic boundary conditions for three different electron concentrations: a single electron, two…
We generalize the Momentum Average approximations MA$^{(0)}$ and MA$^{(1)}$ to study the effects of coupling to multiple optical phonons on the properties of a Holstein polaron. As for a single phonon mode, these approximations are…
An exact diagonalization technique is used to investigate the low-lying excited polaron states in the Holstein model for the infinite one-dimensional lattice. For moderate values of the adiabatic ratio, a new and comprehensive picture,…
The Holstein model often serves as an archetype for electron-phonon interactions and polaron formation in solids. However, precise descriptions of the Holstein polaron are difficult when the phonon frequency is small and the electron-phonon…
The single-polaron band structure of the Holstein model in one and two dimensions is studied using a new form of resummed strong-coupling perturbation theory. Well converged results are obtained for phonon frequencies of the order of the…
A recently developed quantum Monte Carlo approach to the Holstein model with one electron [PRB 69, 024301 (2004)] is extended to two and three dimensional lattices. A moderate sign problem occurs, which is found to diminish with increasing…