Finite-entanglement properties in the matrix product states of the one-dimensional Hubbard model

Abstract

We study the effects of limited entanglement in the one-dimensional Hubbard model by representing the ground states in the form of matrix product states. Finite-entanglement scaling behavior over a wide range is observed at half-filling. The critical exponents characterizing the length scale in terms of the size of the matrices used are obtained, confirming the theoretical prediction that the values of the exponents are solely determined by the central charge. The entanglement spectrum shows that a global double degeneracy occurs in the ground states with a charge gap. We also find that the Mott transition, tuned by changing the chemical potential, always occurs through a first-order transition, and the metallic phase has a few conducting states, including the states with a mean-field nature close to the critical point, as expected in variational matrix product states with a finite amount of entanglement.