Ferromagnetic contacts put in proximity with carbon nanotubes induce spin and orbital polarizations. These polarizations affect dramatically the Kondo correlations occurring in quantum dots formed in a carbon nanotube, inducing effective fields in both spin and orbital sectors. As a consequence, the carbon nanotube quantum dot spectral density shows a fourfold split SU(4) Kondo resonance. Furth...

Submitted for the MAR06 Meeting of The American Physical Society Stability of the quantum spin Hall effect with disorder and interactions CENKE XU, JOEL MOORE, University of California Berkeley — The stability to interactions and disorder of the quantum spin Hall effect (QSHE) proposed for time-reversal-invariant 2D systems is discussed. The QSHE requires an energy gap in the bulk and gapless e...

The magnetic response of a Kramers doublet is analyzed in a general case taking into account only the formal properties derived from time reversal operation. It leads to a definition of a matrix G (gyromagnetic matrix) whose expression depends on the chosen reference frame and on the Kramers conjugate basis used to describe the physical system. It is shown that there exists a reference frame an...

We consider a Ginzburg–Landau partial differential equation in a bounded interval, perturbed by weak spatio–temporal noise. As the interval length increases, a transition between activation regimes occurs, in which the classical Kramers rate diverges [MS01]. We determine a corrected Kramers formula at the transition point, yielding a finite, though noise-dependent rate prefactor, confirming a c...

We reconsider the importance of statistical fluctuations for fission dynamics beyond the saddle in the light of recent evaluations of transport coefficients for average motion. The size of these fluctuations are estimated by means of the Kramers-Ingold solution for the inverted oscillator, which allows for an inclusion of quantum effects. PACS: 5.40+j, 5.60+w, 24.10 Pa, 24.60.-k Kramers’ transp...

We consider operators of Kramers-Fokker-Planck type in the semi-classical limit such that the exponent of the associated Maxwellian is a Morse function with two local minima and a saddle point. Under suitable additional assumptions we establish the complete asymptotics of the exponentially small splitting between the first two eigenvalues. Résumé On considère des opérateurs du type de Kramers-F...

Magnetization reversal in a ferromagnetic nanowire which is much narrower than the exchange length is believed to be accomplished through the thermally activated growth of a spatially localized nucleus, which initially occupies a small fraction of the total volume. To date, the most detailed theoretical treatments of reversal as a field-induced but noise-activated process have focused on the ca...

In this paper, we study theoretically a pump–probe model for the Kramers–Kronig (KK) relations during laser operation. A solution of laser equations reveals that the dispersion profile of a saturated laser gain medium is non-analytical at the boundary between the lasing and the non-lasing spectral region. Such a non-analyticity cannot be explained in terms of the KK relations. In order to inter...