22,042 research outputs found
Simple Non-Markovian Microscopic Models for the Depolarizing Channel of a Single Qubit
The archetypal one-qubit noisy channels ---depolarizing, phase-damping and
amplitude-damping channels--- describe both Markovian and non-Markovian
evolution. Simple microscopic models for the depolarizing channel, both
classical and quantum, are considered. Microscopic models which describe phase
damping and amplitude damping channels are briefly reviewed.Comment: 13 pages, 2 figures. Title corrected. Paper rewritten. Added
references. Some typos and errors corrected. Author adde
Anomalies and O-plane charges in orientifolded brane tilings
We investigate orientifold of brane tilings. We clarify how the cancellations
of gauge anomaly and Witten's anomaly are guaranteed by the conservation of the
D5-brane charge. We also discuss the relation between brane tilings and the
dual Calabi-Yau cones realized as the moduli spaces of gauge theories. Two
types of flavor D5-branes in brane tilings and corresponding superpotentials of
fundamental quark fields are proposed, and it is shown that the massless loci
of these quarks in the moduli space correctly reproduce the worldvolume of
flavor D7-branes in the Calabi-Yau cone dual to the fivebrane system.Comment: 46 pages, 19 figure
Switchable resonant coupling of flux qubits
We propose a coupling scheme, where two or more flux qubits with different
eigenfrequencies share Josephson junctions with a coupler loop devoid of its
own quantum dynamics. Switchable two-qubit coupling is realized by tuning the
frequency of the AC magnetic flux through the coupler to a combination
frequency of two of the qubits. The coupling allows any or all of the qubits to
be simultaneously at the degeneracy point and can change sign.Comment: REVTeX 4, 4 pages, 2 figures, v2: reference added, v3: final version
published in Phys. Rev.
Meta-Stable Brane Configuration and Gauged Flavor Symmetry
Starting from an N=1 supersymmetric electric gauge theory with the gauge
group Sp(N_c) x SO(2N_c') with fundamentals for the first gauge group factor
and a bifundamental, we apply Seiberg dual to the symplectic gauge group only
and arrive at the N=1 supersymmetric dual magnetic gauge theory with dual
matters including the gauge singlets and superpotential. By analyzing the
F-term equations of the dual magnetic superpotential, we describe the
intersecting brane configuration of type IIA string theory corresponding to the
meta-stable nonsupersymmetric vacua of this gauge theory.Comment: 16 pp, 3 figures; stability analysis in page 7 and 8 added and the
presentation improved; reduced bytes of figures and to appear in MPL
Brane Configurations for Nonsupersymmetric Meta-Stable Vacua in SQCD with Adjoint Matter
We present the configurations of intersecting branes in type IIA string
theory corresponding to the meta-stable supersymmetry breaking
vacua(hep-th/0608063) in the four-dimensional N=1 supersymmetric Yang-Mills
theory coupled massive flavors with adjoint matter where the superpotential has
three deformed terms.Comment: 15pp, 3 figures; The last two sentences in page 7 corrected; The last
figure added;improved pages 10 and 11;figures corrected;the references to
colors improved in the text and to appear in CQ
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