Gaussian Matrix Product States
arXiv:1201.3945
Abstract
We introduce Gaussian Matrix Product States (GMPS), a generalization of Matrix Product States (MPS) to lattices of harmonic oscillators. Our definition resembles the interpretation of MPS in terms of projected maximally entangled pairs, starting from which we derive several properties of GMPS, often in close analogy to the finite dimensional case: We show how to approximate arbitrary Gaussian states by MPS, we discuss how the entanglement in the bonds can be bounded, we demonstrate how the correlation functions can be computed from the GMPS representation, and that they decay exponentially in one dimension, and finally relate GMPS and ground states of local Hamiltonians.
This work originally appeared as Sec. VII of quant-ph/0509166, and is published in the Proceedings on the conference on Quantum information and many body quantum systems, edited by M. Ericsson and S. Montangero, pg. 129 (Edizioni della Normale, Pisa, 2008)