35 research outputs found
NMR Simulation of an Eight-State Quantum System
The propagation of excitation along a one-dimensional chain of atoms is
simulated by means of NMR. The physical system used as an analog quantum
computer is a nucleus of 133-Cs (spin 7/2) in a liquid crystalline matrix. The
Hamiltonian of migration is simulated by using a special 7-frequency pulse, and
the dynamics is monitored by following the transfer of population from one of
the 8 spin energy levels to the other.Comment: 10 pages, 3 figure
Experimental realization of a continuous version of the Grover algorithm
A continuous, analog version of the Grover algorithm is realized using NMR.
The system studied is 23Na in a liquid crystal medium. The presence of
quadrupolar coupling makes the spin I=3/2 nucleus a 2-qubit system. Applying a
specially designed pulse sequence, the time evolution of the spin density
operator is described in an interaction representation which has no external
time-dependent radio-frequency fields. This approach is used to implement one
instance of the continuous Grover search for the transform of a uniform state
to a target state, and the implementation provides a clear physical
interpretation of the algorithm. The experimental results are in good agreement
with the theory.Comment: 14 pages plus 2 figures, accepted for publication in Phys. Rev.