We consider an open quantum system of N not directly interacting spins qubits in contact with both local and collective thermal environments. The qubit-environment interactions are energy conserving. We trace out the variables of the thermal environments and N − 2 qubits to obtain the time-dependent reduced density matrix for two arbitrary qubits. We numerically simulate the reduced dynamics and the creation of entanglement concurrence as a function of the parameters of the thermal environments and the number of qubits, N. Our results demonstrate that the two- qubit entanglement generally decreases as N increases. We show analytically that, in the limit N → ∞, no entanglement can be created. This indicates that collective thermal environments cannot create two-qubit entanglement when many qubits are located within a region of the size of the environment coherence length. We discuss possible relevance of our consideration to recent quantum information devices and biosystems.

Merkli, M., Berman, G., Borgonovi, F., Tsifrinovich, V., Creation of Two-Particle Entanglement in Open Macroscopic Quantum Systems, <<ADVANCES IN MATHEMATICAL PHYSICS>>, 2012; 2012 (Marzo): 1-15. [doi:10.1155/2012/375182] [http://hdl.handle.net/10807/23403]

Creation of Two-Particle Entanglement in Open Macroscopic Quantum Systems

Merkli, Marco;Borgonovi, Fausto;
2012

Abstract

We consider an open quantum system of N not directly interacting spins qubits in contact with both local and collective thermal environments. The qubit-environment interactions are energy conserving. We trace out the variables of the thermal environments and N − 2 qubits to obtain the time-dependent reduced density matrix for two arbitrary qubits. We numerically simulate the reduced dynamics and the creation of entanglement concurrence as a function of the parameters of the thermal environments and the number of qubits, N. Our results demonstrate that the two- qubit entanglement generally decreases as N increases. We show analytically that, in the limit N → ∞, no entanglement can be created. This indicates that collective thermal environments cannot create two-qubit entanglement when many qubits are located within a region of the size of the environment coherence length. We discuss possible relevance of our consideration to recent quantum information devices and biosystems.
Inglese
Merkli, M., Berman, G., Borgonovi, F., Tsifrinovich, V., Creation of Two-Particle Entanglement in Open Macroscopic Quantum Systems, <<ADVANCES IN MATHEMATICAL PHYSICS>>, 2012; 2012 (Marzo): 1-15. [doi:10.1155/2012/375182] [http://hdl.handle.net/10807/23403]
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10807/23403
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 3
social impact