The generation of Greenberger-Horne-Zeilinger (GHZ) states is a crucial problem in quantum information. We derive general conditions for obtaining GHZ states as eigenstates of a Hamiltonian. We find that a necessary condition for an n-qubit GHZ state to be a nondegenerate eigenstate of a Hamiltonian is the presence of m-qubit couplings with m[(n+1)/2]. Moreover, we introduce a Hamiltonian with a GHZ eigenstate and derive sufficient conditions for the removal of the degeneracy. © 2011 American Physical Society.
Greenberger-Horne-Zeilinger states and few-body Hamiltonians / Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio; Pepe, Francesco V.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 107:26(2011). [10.1103/PhysRevLett.107.260502]
Greenberger-Horne-Zeilinger states and few-body Hamiltonians
FLORIO, Giuseppe;
2011-01-01
Abstract
The generation of Greenberger-Horne-Zeilinger (GHZ) states is a crucial problem in quantum information. We derive general conditions for obtaining GHZ states as eigenstates of a Hamiltonian. We find that a necessary condition for an n-qubit GHZ state to be a nondegenerate eigenstate of a Hamiltonian is the presence of m-qubit couplings with m[(n+1)/2]. Moreover, we introduce a Hamiltonian with a GHZ eigenstate and derive sufficient conditions for the removal of the degeneracy. © 2011 American Physical Society.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
