114 research outputs found
Kondo and Dicke effect in quantum-dots side coupled to a quantum wire
Electron tunneling through quantum-dots side coupled to a quantum wire, in
equilibrium and nonequilibrium Kondo regime, is studied. The mean-field
finite- slave-boson formalism is used to obtain the solution of the problem.
We have found that the transmission spectrum shows a structure with two
anti-resonances localized at the renormalized energies of the quantum dots. The
DOS of the system shows that when the Kondo correlations are dominant there are
two Kondo regimes with its own Kondo temperature. The above behavior of the DOS
can be explained by quantum interference in the transmission through the two
different resonance states of the quantum dots coupled to common leads. This
result is analogous to the Dicke effect in optics. We investigate the many body
Kondo states as a function of the parameters of the system.Comment: 5 figures. To appear in Phys. Rev.
Środki zabezpieczające w znowelizowanym kodeksie karnym
The issue of the article are precautions reformed by the Act of 20 February 2015. The following were discussed: the purpose of precautions, the principles of their predications (the principles of necessity and proportionality), a catalog of precautions, including an electronic control of location, therapy, therapy of addictions, stay in the psychiatric unit, measures of an administrative nature, presumptions to predicate precautions, namely committing a criminal act in the state of insanity or limited soundness of mind, a conviction for certain offenses in relation to the disorder of sexual preferences or personality disorder, a conviction for an offense committed in connection with alcohol addiction, intoxicant addiction or other substance with similar effect, the duration of precautions, predication of precautions after the sentence and renewed predication of a precaution.The issue of the article are precautions reformed by the Act of 20 February 2015. The following were discussed: the purpose of precautions, the principles of their predications (the principles of necessity and proportionality), a catalog of precautions, including an electronic control of location, therapy, therapy of addictions, stay in the psychiatric unit, measures of an administrative nature, presumptions to predicate precautions, namely committing a criminal act in the state of insanity or limited soundness of mind, a conviction for certain offenses in relation to the disorder of sexual preferences or personality disorder, a conviction for an offense committed in connection with alcohol addiction, intoxicant addiction or other substance with similar effect, the duration of precautions, predication of precautions after the sentence and renewed predication of a precaution
Hemodynamic phenotypes and its association with blood pressure changes at continuous positive airway pressure therapy in obstructive sleep apnoea hypertensive patients
Background. The goal of our study was to define the hemodynamic phenotypes in hypertensive patients with newly diagnosed obstructive sleep apnoea (OSA) using the individual modelling of hemodynamics derived from ambulatory blood pressure monitoring (ABPM), a method proposed by our group previously, and to assess its validity in blood pressure alterations secondary to continuous positive airway pressure (CPAP).
Material and methods. Thirty-three hypertensive patients with moderate-to-severe OSA were investigated. All patients underwent ABPM on two occasions: at baseline and after one week CPAP. The sets of BP indexes at first ABPM were used for individual modelling to define the hemodynamic phenotype (class) based on regression analyses; specifically, the phenotypes were defined for daytime, nighttime and for 24 hours. The CPAP therapy efficacy was predefined as improvement in BP nighttime decrease for additional 5% as compared to baseline ABPM. With reference to this criterion, patients were further classified as responders (who achieved this target), and non-responders.
Results. Only 21.2% of hypertensive patients with OSA had optimal hemodynamic phenotype (class H2), despite comprehensive antihypertensive therapy; most of the other patients were classified either as harmonic type (class H3; 39.4%), or of diastolic dysfunctional type (class D3; 15.2%). In the daytime period 18.2% of patients with OSA were classified as D1-class, which is associated with high risk of acute hypotensive episodes. Responders were more frequently characterized by phenotype H3 (daytime) vs. nonresponders: 53.3% and 5.6% respectively; P < 0.05. At nighttime non-responders were more likely to transform the different baseline classes into H3 and D2; P < 0.05 vs. responders.
Conclusion. Our study suggest utility of newly developed modelling based on hemodynamic BP indexes in the prediction of BP alterations secondary to CPAP in OSA hypertensive patients
Towards the All-Loop Worldsheet S Matrix for AdS3 × S3 × T4
We obtain the all-loop worldsheet S matrix for fundamental excitations on AdS3 × S3 × T4 by studying the off-shell symmetry algebra of the superspace action in light cone gauge. The massless modes, unaccounted for in earlier works, are automatically included in our treatment. Their exact dispersion relation is found to be nonrelativistic, of giant-magnon form, and their scattering is naturally well defined. This opens the way to a complete investigation of AdS3/CFT2 integrability
Entanglement and transport through correlated quantum dot
We study quantum entanglement in a single-level quantum dot in the
linear-response regime. The results show, that the maximal quantum value of the
conductance 2e^2/h not always match the maximal entanglement. The pairwise
entanglement between the quantum dot and the nearest atom of the lead is also
analyzed by utilizing the Wootters formula for charge and spin degrees of
freedom separately. The coexistence of zero concurrence and the maximal
conductance is observed for low values of the dot-lead hybridization. Moreover,
the pairwise concurrence vanish simultaneously for charge and spin degrees of
freedom, when the Kondo resonance is present in the system. The values of a
Kondo temperature, corresponding to the zero-concurrence boundary, are also
provided.Comment: Presented on the International Conference "Nanoelectronics '06", 7-8
January 2006, Lancaster, U
Landau-Lifshitz sigma-models, fermions and the AdS/CFT correspondence
We define Landau-Lifshitz sigma models on general coset space , with
a maximal stability sub-group of . These are non-relativistic models that
have -valued N\"other charges, local invariance and are classically
integrable. Using this definition, we construct the
Landau-Lifshitz sigma-model. This sigma model describes the thermodynamic limit
of the spin-chain Hamiltonian obtained from the complete one-loop dilatation
operator of the N=4 super Yang-Mills (SYM) theory. In the second part of the
paper, we identify a number of consistent truncations of the Type IIB
Green-Schwarz action on whose field content consists of two
real bosons and 4,8 or 16 real fermions. We show that -symmetry acts
trivially in these sub-sectors. In the context of the large spin limit of the
AdS/CFT correspondence, we map the Lagrangians of these sub-sectors to
corresponding truncations of the Landau-Lifshitz
sigma-model.Comment: 42 page
More on integrable structures of superstrings in AdS(4) x CP(3) and AdS(2) x S(2) x T(6) superbackgrounds
In this paper we continue the study, initiated in arXiv:1009.3498 and
arXiv:1104.1793, of the classical integrability of Green-Schwarz superstrings
in AdS(4) x CP(3) and AdS(2) x S(2) x T(6) superbackgrounds whose spectrum
contains non-supercoset worldsheet degrees of freedom corresponding to broken
supersymmetries in the bulk. We derive an explicit expression, to all orders in
the coset fermions and to second order in the non-coset fermions, which extends
the supercoset Lax connection in these backgrounds with terms depending on the
non-coset fermions. An important property of the obtained form of the Lax
connection is that it is invariant under Z_4-transformations of the
superisometry generators and the spectral parameter. This demonstrates that the
contribution of the non-coset fermions does not spoil the Z_4-symmetry of the
super-coset Lax connection which is of crucial importance for the application
of Bethe-ansatz techniques. The expressions describing the AdS(4) x CP(3) and
AdS(2) x S(2) x T(6) superstring sigma--models and their Lax connections have a
very similar form. This is because their amount of target-space supersymmetries
complement each other to 32=24+8, the maximal number of 10d type II
supersymmetries. As a byproduct, this similarity has allowed us to obtain the
form of the geometry of the complete type IIA AdS(2) x S(2) x T(6) superspace
to all orders in the coset fermions and to the second order in the non-coset
ones.Comment: 28 pages; v2: References adde
Dirichlet Branes on Orientifolds
We consider the classification of BPS and non-BPS D-branes in orientifold
models. In particular we construct all stable BPS and non-BPS D-branes in the
Gimon-Polchinski (GP) and Dabholkar-Park-Blum-Zaffaroni (DPBZ) orientifolds and
determine their stability regions in moduli space as well as decay products. We
find several kinds of integrally and torsion charged non-BPS D-branes. Certain
of these are found to have projective representations of the orientifold
GSO group on the Chan-Paton factors. It is found that the GP
orientifold is not described by equivariant orthogonal K-theory as may have
been at first expected. Instead a twisted version of this K-theory is expected
to be relevant.Comment: 33 pages, LaTeX, 5 figures. v2 typos corrected, references included,
(4,s)-branes re-examine
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Quantum Spectral Curve for AdS3/CFT2: a proposal
We conjecture the Quantum Spectral Curve equations for string theory on AdS3×S3×T4 with RR charge and its CFT2 dual. We show that in the large-length regime, under additional mild assumptions, the QSC reproduces the Asymptotic Bethe Ansatz equations for the massive sector of the theory, including the exact dressing phases found in the literature. The structure of the QSC shares many similarities with the previously known AdS5 and AdS4 cases, but contains a critical new feature - the branch cuts are no longer quadratic. Nevertheless, we show that much of the QSC analysis can be suitably generalised producing a self-consistent system of equations. While further tests are necessary, particularly outside the massive sector, the simplicity and self-consistency of our construction suggests the completeness of the QSC
Kondo effect in side coupled double quantum-dot molecule
Electron tunneling through a double quantum dot molecule side attached to a
quantum wire, in the Kondo regime, is studied. The mean-field finite-U
slave-boson formalism is used to obtain the solution of the problem. We found
conductance cancelations when the molecular energies of the side attached
double quantum-dot cross the Fermi energy. We investigate the many body
molecular Kondo states as a function of the parameters of the system.Comment: 12 pages, 7 figures. Submitted to Solid State Com
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