77 research outputs found
Experimental demonstration of stimulated polarization wave in a chain of nuclear spins
A stimulated wave of polarization, which implements a simple mechanism of
quantum amplification, is experimentally demonstrated in a chain of four
J-coupled nuclear spins, irradiated by a weak radio-frequency transverse field.
The "quantum domino" dynamics, a wave of flipped spins triggered by a flip of
the first spin, has been observed in fully C-labeled sodium butyrate.Comment: 8 pages including 3 figure
Projective measurement in nuclear magnetic resonance
It is demonstrated that nuclear magnetic resonance experiments using
pseudopure spin states can give possible outcomes of projective quantum
measurement and probabilities of such outcomes. The physical system is a
cluster of six dipolar-coupled nuclear spins of benzene in a liquid-crystalline
matrix. For this system with the maximum total spin S=3, the results of
measuring are presented for the cases when the state of the system is one
of the eigenstates of .Comment: 9 pages incluing 3 figure
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
Selective excitation of homogeneous spectral lines
It is possible, for homogeneously broadened lines, to excite selectively the
response signals, which are orders of magnitude narrower than the original
lines. The new type of echo, which allows detecting such signals, and the
formalism, useful for understanding the phenomenon, as well as the experimental
examples from NMR spectroscopy are presented.Comment: 19 pages, 8 figure
Preparation of pseudopure state in a cluster of dipolar-coupled spins with "unresolved" spectrum
A method of creating pseudopure spin states in large clusters of coupled
spins is described. It is based on filtering multiple-quantum coherence of the
highest order followed by a time-reversal period and partial saturation.
Experimental demonstration is presented for a cluster of six dipolar-coupled
proton spins of a benzene molecule in liquid crystalline matrix, and the
details of spin dynamics are studied numerically.Comment: 15 pages, 3 figures, submitted to Phys. Rev.
Twelve-spin "Schrodinger cat"
Pseudopure "cat" state, a superposition of quantum states with all spins up
and all spins down, is experimentally demonstrated for a system of twelve
dipolar-coupled nuclear spins of fully 13C-labeled benzene molecule oriented in
a liquid-crystalline matrix.Comment: Submitted to Applied Physics Letter
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