577 research outputs found
The high probability state transfers and entanglements between different nodes of the homogeneous spin 1/2 chain in inhomogeneous external magnetic field
We consider the high probability state transfers and entanglements between
different nodes of the spin-1/2 chains governed by the XXZ-Hamiltonian using
the inhomogeneous stationary external magnetic field. Examples of three-,
four-, ten- and twenty-node chains are represented. A variant of realization of
the proper inhomogeneous magnetic field is discussed.Comment: 16 pages, 2 figure
The multiple quantum NMR dynamics in systems of equivalent spins with the dipolar ordered initial state
The multiple quantum (MQ) NMR dynamics in the system of equivalent spins with
the dipolar ordered initial state is considered. The high symmetry of the MQ
Hamiltonian is used in order to develop the analytical and numerical methods
for an investigation of the MQ NMR dynamics in the systems consisting of
hundreds of spins from "the first principles". We obtain the dependence of the
intensities of the MQ NMR coherences on their orders (profiles of the MQ NMR
coherences) for the systems of spins. It is shown that these
profiles may be well approximated by the exponential distribution functions. We
also compare the MQ NMR dynamics in the systems of equivalent spins having two
different initial states, namely the dipolar ordered state and the thermal
equilibrium state in the strong external magnetic field.Comment: 11 pages 4 figure
Relationship between probabilities of the state transfers and entanglements in spin systems with simple geometrical configurations
In this paper we derive analytical relations between probabilities of the
excited state transfers and entanglements calculated by both the Wootters and
positive partial transpose (PPT) criteria for the arbitrary spin system with
single excited spin in the external magnetic field and Hamiltonian commuting
with . We apply these relations to study the arbitrary state transfers and
entanglements in the simple systems of nuclear spins having two- and
three-dimensional geometrical configurations with Hamiltonian. It is
shown that High-Probability State Transfers (HPSTs) are possible among all four
nodes placed in the corners of the rectangle with the proper ratio of sides as
well as among all eight nodes placed in the corners of the parallelepiped with
the proper ratio of sides. Entanglements responsible for these HPSTs have been
identified.Comment: 27pages, 10 figure
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