Continuous-time quantum Monte Carlo studies of lattice polarons
Paul E. Spencer
2134/33799
https://repository.lboro.ac.uk/articles/thesis/Continuous-time_quantum_Monte_Carlo_studies_of_lattice_polarons/9410222
The polaron problem is studied, on an infinite lattice, using the continuous-time path-integral
quantum Monte Carlo scheme The method is based on the Feynman technique to analytically
integrate out the phonon degrees of freedom. The transformed problem is that of a single electron
with retarded self-interaction in imaginary time. The Metropolis algorithm is used to sample an
ensemble of electron trajectories with twisted (rather than periodic) boundary conditions in imaginary time, which allows dynamic properties of the system to by measured directly. The
method is numerically "exact", in the sense that there are no systematic errors due to finite
system size, trotter decomposition or finite temperature The implementation of the algorithm
in continuous imaginary time dramatically increases computational efficiency compared with the
traditional discrete imaginary time algorithms. [Continues.]
2018-07-09 11:52:22
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Physical Sciences not elsewhere classified