Interior eigenstates of strongly correlated quantum systems

Abstract

We present a new method to compute states of quantum spin systems with high energy and low energy variance. Such states appear to play an important role in investigating current open problems in condensed matter physics. By minimizing the energy variance with a modification of the power method algorithm we obtain, from initial random states, states with low energy variance and their energy located in the middle of the spectrum. We test our method for a system of eight particles, four different instances of the Heisenberg model and one of the Ising model