Exact diagonalization

Area Laws

Introduction

The eigenspectrum of a Hamiltonian operator encodes fundamental properties of a quantum system. While the ground state and low-lying excitations are often the primary focus – governing low-temperature physics and phase transitions – many problems require access to the interior of the spectrum. For instance, studying thermalization, many-body localization, or excited state quantum phase transitions often necessitates computing eigenstates in the middle of the spectrum.