132 research outputs found
The Coulomb Branch of Yang-Mills Theory from the Schroedinger Representation
The Coulomb branch of the potential between two static colored sources is
calculated for the Yang-Mills theory using the electric Schroedinger
representation.Comment: 4 pages, no figures, REVTEX, as in Phys. Lett.
Quantum computation with abelian anyons on the honeycomb lattice
We consider a two-dimensional spin system that exhibits abelian anyonic
excitations. Manipulations of these excitations enable the construction of a
quantum computational model. While the one-qubit gates are performed
dynamically the model offers the advantage of having a two-qubit gate that is
of topological nature. The transport and braiding of anyons on the lattice can
be performed adiabatically enjoying the robust characteristics of geometrical
evolutions. The same control procedures can be used when dealing with
non-abelian anyons. A possible implementation of the manipulations with optical
lattices is developed.Comment: 4 pages, 3 figures, REVTEX, improved presentation and implementatio
Detecting Majorana bound states
We propose a set of interferometric methods on how to detect Majorana bound
states induced by a topological insulator. The existence of these states can be
easily determined by the conductance oscillations as function of magnetic flux
and/or electric voltage. We study the system in the presence and absence of
Majorana bound states and observe strikingly different behaviors. Importantly,
we show that the presence of coupled Majorana bound states can induce a
persistent current in absence of any external magnetic field.Comment: 7 pages, 6 figures, 1 table, revised and expanded, accepted for
publication in Phys. Rev.
The Schrodinger representation for ϕ(^4) theory and the O(N) σ-model
In this work we apply the field theoretical Schrodinger representation to the massive ϕ(^4) theory and the O(N) σ model in 1 + 1 dimensions. The Schrodinger equation for the ϕ(^4) theory is reviewed and then solved classically and semiclassically, to obtain the vacuum functional as an expansion of local functionals. These results are compared with equivalent ones derived from the path integral formulation to prove their agreement with the conventional field theoretical methods. For the O(N) a model we construct the functional Laplacian, which is the principal ingredient of the corresponding Schrodinger equation. This result is used to construct the generalised Virasoro operators for this model and study their algebra
Effective three-body interactions in triangular optical lattices
We demonstrate that a triangular optical lattice of two atomic species,
bosonic or fermionic, can be employed to generate a variety of novel spin-1/2
Hamiltonians. These include effective three-spin interactions resulting from
the possibility of atoms tunneling along two different paths. Such interactions
can be employed to simulate particular one or two dimensional physical systems
with ground states that possess a rich structure and undergo a variety of
quantum phase transitions. In addition, tunneling can be activated by employing
Raman transitions, thus creating an effective Hamiltonian that does not
preserve the number of atoms of each species. In the presence of external
electromagnetic fields, resulting in complex tunneling couplings, we obtain
effective Hamiltonians that break chiral symmetry. The ground states of these
Hamiltonians can be used for the physical implementation of geometrical or
topological objects.Comment: 10 pages, 5 figures, REVTEX. Experimental implementation elaborated,
brief study of ground states give
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