1 research outputs found
Ground state fidelity from tensor network representations
For any D-dimensional quantum lattice system, the fidelity between two ground
state many-body wave functions is mapped onto the partition function of a
D-dimensional classical statistical vertex lattice model with the same lattice
geometry. The fidelity per lattice site, analogous to the free energy per site,
is well-defined in the thermodynamic limit and can be used to characterize the
phase diagram of the model. We explain how to compute the fidelity per site in
the context of tensor network algorithms, and demonstrate the approach by
analyzing the two-dimensional quantum Ising model with transverse and parallel
magnetic fields.Comment: 4 pages, 2 figures. Published version in Physical Review Letter