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.
Zhou
Huan-Qiang
HQ
Department of Physics, Chongqing University, Chongqing 400044, The People's Republic of China.
Orús
Roman
R
Vidal
Guifre
G