1,498 research outputs found
Gapped quantum liquids and topological order, stochastic local transformations and emergence of unitarity
In this work we present some new understanding of topological order,
including three main aspects: (1) It was believed that classifying topological
orders corresponds to classifying gapped quantum states. We show that such a
statement is not precise. We introduce the concept of \emph{gapped quantum
liquid} as a special kind of gapped quantum states that can "dissolve" any
product states on additional sites. Topologically ordered states actually
correspond to gapped quantum liquids with stable ground-state degeneracy.
Symmetry-breaking states for on-site symmetry are also gapped quantum liquids,
but with unstable ground-state degeneracy. (2) We point out that the
universality classes of generalized local unitary (gLU) transformations
(without any symmetry) contain both topologically ordered states and
symmetry-breaking states. This allows us to use a gLU invariant -- topological
entanglement entropy -- to probe the symmetry-breaking properties hidden in the
exact ground state of a finite system, which does not break any symmetry. This
method can probe symmetry- breaking orders even without knowing the symmetry
and the associated order parameters. (3) The universality classes of
topological orders and symmetry-breaking orders can be distinguished by
\emph{stochastic local (SL) transformations} (i.e.\ \emph{local invertible
transformations}): small SL transformations can convert the symmetry-breaking
classes to the trivial class of product states with finite probability of
success, while the topological-order classes are stable against any small SL
transformations, demonstrating a phenomenon of emergence of unitarity. This
allows us to give a new definition of long-range entanglement based on SL
transformations, under which only topologically ordered states are long-range
entangled.Comment: Revised version. Figures and references adde
The production and decay of the top partner in the left-right twin higgs model at the ILC and CLIC
The left-right twin Higgs model (LRTHM) predicts the existence of the top
partner . In this work, we make a systematic investigation for the single
and pair production of this top partner through the processes:
e^{+}e^{-}\to t\ov{T} + T\bar{t} and T\ov{T}, the neutral scalar (the
SM-like Higgs boson or neutral pseudoscalar boson ) associate
productions e^{+}e^{-}\to t\ov{T}h +T\bar{t}h, T\ov{T}h,
t\ov{T}\phi^{0}+T\bar{t}\phi^{0} and T\ov{T}\phi^{0}. From the numerical
evaluations for the production cross sections and relevant phenomenological
analysis we find that (a) the production rates of these processes, in the
reasonable parameter space, can reach the level of several or tens of fb; (b)
for some cases, the peak value of the resonance production cross section can be
enhanced significantly and reaches to the level of pb; (c) the subsequent decay
of may generate typical phenomenological
features rather different from the signals from other new physics models beyond
the standard model(SM); and (d) since the relevant SM background is generally
not large, some signals of the top partner predicted by the LRTHM may be
detectable in the future ILC and CLIC experiments.Comment: 20pages, 15 figures and 6 Tables. Minor corrections on text. new
references adde
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