3,337 research outputs found
Entanglement of a 3D generalization of the Kitaev model on the diamond lattice
We study the entanglement properties of a three dimensional generalization of
the Kitaev honeycomb model proposed by Ryu [Phys. Rev. B 79, 075124, (2009)].
The entanglement entropy in this model separates into a contribution from a
gauge field and that of a system of hopping Majorana fermions, similar to
what occurs in the Kitaev model. This separation enables the systematic study
of the entanglement of this 3D interacting bosonic model by using the tools of
non-interacting fermions. In this way, we find that the topological
entanglement entropy comes exclusively from the gauge field, and that it
is the same for all of the phases of the system. There are differences,
however, in the entanglement spectrum of the Majorana fermions that distinguish
between the topologically distinct phases of the model. We further point out
that the effect of introducing vortex lines in the gauge field will only
change the entanglement contribution of the Majorana fermions. We evaluate this
contribution to the entanglement which arises due to gapless Majorana modes
that are trapped by the vortex lines.Comment: 25 pages, 5 figures. Invited article to JSTAT Special Issue: Quantum
Entanglement in Condensed Matter Physic
Many-body mobility edge due to symmetry-constrained dynamics and strong interactions
We provide numerical evidence combined with an analytical understanding of
the many-body mobility edge for the strongly anisotropic spin-1/2 XXZ model in
a random magnetic field. The system dynamics can be understood in terms of
symmetry-constrained excitations about parent states with ferromagnetic and
anti-ferromagnetic short range order. These two regimes yield vastly different
dynamics producing an observable, tunable many-body mobility edge. We compute a
set of diagnostic quantities that verify the presence of the mobility edge and
discuss how weakly correlated disorder can tune the mobility edge further.Comment: 10 pages, 5 figure
Yukawa terms in noncommutative SO(10) and E6 GUTs
We propose a method for constructing Yukawa terms for noncommutative SO(10)
and E6 GUTs, when these GUTs are formulated within the enveloping-algebra
formalism. The most general noncommutative Yukawa term that we propose
contains, at first order in thetamunu, the most general BRS invariant Yukawa
contribution whose only dimensionful parameter is the noncommutativity
parameter. This noncommutative Yukawa interaction is thus renormalisable at
first order in thetamunu.Comment: 14 pages, no figure
Structure formation in the presence of relativistic heat conduction: corrections to the Jeans wave number with a stable first order in the gradients formalism
The problem of structure formation in relativistic dissipative fluids was
analyzed in a previous work within Eckart's framework, in which the heat flux
is coupled to the hydrodynamic acceleration, additional to the usual
temperature gradient term. It was shown that in such case, the pathological
behavior of fluctuations leads to the disapperance of the gravitational
instability responsible for structure formation. In the present work the
problem is revisited now using a constitutive equation derived from
relativistic kinetic theory. The new relation, in which the heat flux is not
coupled to the hydrodynamic acceleration, leads to a consistent first order in
the gradients formalism. In this case the gravitational instability remains,
and only relativistic corrections to the Jeans wave number are obtained. In the
calculation here shown the non-relativistc limit is recovered, opposite to what
happens in Eckart's case.Comment: 10 pages, no figure
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