15,683 research outputs found
Schemes of implementation in NMR of quantum processors and Deutsch-Jozsa algorithm by using virtual spin representation
Schemes of experimental realization of the main two qubit processors for
quantum computers and Deutsch-Jozsa algorithm are derived in virtual spin
representation. The results are applicable for every four quantum states
allowing the required properties for quantum processor implementation if for
qubit encoding virtual spin representation is used. Four dimensional Hilbert
space of nuclear spin 3/2 is considered in details for this aimComment: 15 pages, 3 figure
Cubic interactions of massless bosonic fields in three dimensions II: Parity-odd and Chern-Simons vertices
This work completes the classification of the cubic vertices for arbitrary
spin massless bosons in three dimensions started in a previous companion paper
by constructing parity-odd vertices. Similarly to the parity-even case, there
is a unique parity-odd vertex for any given triple
of massless bosons if the triangle inequalities are satisfied ()
and none otherwise. These vertices involve two (three) derivatives for odd
(even) values of the sum . A non-trivial relation between
parity-even and parity-odd vertices is found. Similarly to the parity-even
case, the scalar and Maxwell matter can couple to higher spins through current
couplings with higher derivatives. We comment on possible lessons for 2d CFT.
We also derive both parity-even and parity-odd vertices with Chern-Simons
fields and comment on the analogous classification in two dimensions.Comment: 29 page
Metric- and frame-like higher-spin gauge theories in three dimensions
We study the relation between the frame-like and metric-like formulation of
higher-spin gauge theories in three space-time dimensions. We concentrate on
the theory that is described by an SL(3) x SL(3) Chern-Simons theory in the
frame-like formulation. The metric-like theory is obtained by eliminating the
generalised spin connection by its equation of motion, and by expressing
everything in terms of the metric and a spin-3 Fronsdal field. We give an exact
map between fields and gauge parameters in both formulations. To work out the
gauge transformations explicitly in terms of metric-like variables, we have to
make a perturbative expansion in the spin-3 field. We describe an algorithm how
to do this systematically, and we work out the gauge transformations to cubic
order in the spin-3 field. We use these results to determine the gauge algebra
to this order, and explain why the commutator of two spin-3 transformations
only closes on-shell.Comment: 26 pages, no figure
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