5–11 Jun 2022
McMaster University
America/Toronto timezone
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Computing excitations in a matrix product state with block Lanczos

8 Jun 2022, 11:30
15m
MDCL 1309 (McMaster University)

MDCL 1309

McMaster University

Oral (Non-Student) / Orale (non-étudiant(e)) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) W1-8 Condensed Matter Theory I (DCMMP/DTP) | Théorie de la matière condensée I (DPMCM/DPT)

Speaker

Thomas Baker

Description

Matrix product state methods are known to be efficient for computing ground states of local, gapped Hamiltonians, particularly in one dimension. We introduce the multi-targeted method that acts on a bundled matrix product state, holding many excitations. The use of a block or banded Lanczos algorithm allows for the simultaneous, variational optimization of the bundle of excitations. The method is demonstrated on a Heisenberg model and other cases of interest. A large number of excitations can be obtained at a small bond dimension with highly reliable local observables throughout the chain. Applications to several models and other cases are also discussed.

Primary author

Thomas Baker

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