Symmetry assisted preparation of entangled many-body states on a quantum computer

Understand

Starting from the Quantum-Phase-Estimate (QPE) algorithm, a method is proposed to construct entangled states that describe correlated many-body systems on quantum computers.

• Using operators for which the discrete set of eigenvalues is known, the QPE approach is followed by measurements that serve as projectors on the entangled states.
• These states can then be used as inputs for further quantum or hybrid quantum-classical processing.
• When the operator is associated to a symmetry of the Hamiltonian, the approach can be seen as a quantum--computer formulation of symmetry breaking followed by symmetry restoration.