scholarly journals ON HAAG DUALITY FOR PURE STATES OF QUANTUM SPIN CHAINS

2008 ◽  
Vol 20 (06) ◽  
pp. 707-724 ◽  
Author(s):  
M. KEYL ◽  
TAKU MATSUI ◽  
D. SCHLINGEMANN ◽  
R. F. WERNER

In this note, we consider quantum spin chains and their translationally invariant pure states. We prove Haag duality for quasilocal observables localized in semi-infinite intervals (-∞ , 0] and [1, ∞) when the von Neumann algebra generated by observables localized in [0, ∞) is non-type I.

2006 ◽  
Vol 18 (09) ◽  
pp. 935-970 ◽  
Author(s):  
M. KEYL ◽  
T. MATSUI ◽  
D. SCHLINGEMANN ◽  
R. F. WERNER

We consider an infinite spin chain as a bipartite system consisting of the left and right half-chains and analyze entanglement properties of pure states with respect to this splitting. In this context, we show that the amount of entanglement contained in a given state is deeply related to the von Neumann type of the observable algebras associated to the half-chains. Only the type I case belongs to the usual entanglement theory which deals with density operators on tensor product Hilbert spaces, and only in this situation separable normal states exist. In all other cases, the corresponding state is infinitely entangled in the sense that one copy of the system in such a state is sufficient to distill an infinite amount of maximally entangled qubit pairs. We apply this results to the critical XY model and show that its unique ground state φS provides a particular example for this type of entanglement.


1992 ◽  
Vol 25 (3) ◽  
pp. 249-258 ◽  
Author(s):  
M. Fannes ◽  
B. Nachtergaele ◽  
R. F. Werner

1994 ◽  
Vol 4 (8) ◽  
pp. 1151-1159 ◽  
Author(s):  
Makoto Idzumi ◽  
Tetsuji Tokihiro ◽  
Masao Arai

RSC Advances ◽  
2015 ◽  
Vol 5 (129) ◽  
pp. 106333-106338 ◽  
Author(s):  
Jun Li ◽  
Bang-Gui Liu

We achieve a powerful life-time expression of the Neel states for arbitrary parameters and show that for famous Fe adatom chains on Cu2N surface, 14 or 16 Fe adatoms are enough to obtain a long life-time for Neel state storage of information.


Sign in / Sign up

Export Citation Format

Share Document