8,063 research outputs found
Chiral field theory of glueball
A chiral field theory of glueball is presented. By adding a
glueball field to a successful Lagrangian of chiral field theory of
pseudoscalar, vector, and axial-vector mesons, the Lagrangian of this theory is
constructed. The couplings between the pseodoscalar glueball field and mesons
are via U(1) anomaly revealed. Qualitative study of the physical processes of
the glueball of is presented. The theoretical
predictions can be used to identify the glueball.Comment: 29 page
Shot noise in resonant tunneling through an interacting quantum dot with intradot spin-flip scattering
In this paper, we present theoretical investigation of the zero-frequency
shot noise spectra in electron tunneling through an interacting quantum dot
connected to two ferromagnetic leads with possibility of spin-flip scattering
between the two spin states by means of the recently developed bias-voltage and
temperature dependent quantum rate equations. For this purpose, a
generalization of the traditional generation-recombination approach is made for
properly taking into account the coherent superposition of electronic states,
i.e., the nondiagonal density matrix elements. Our numerical calculations find
that the Fano factor increases with increasing the polarization of the two
leads, but decreases with increasing the intradot spin-flip scattering.Comment: Some typos correction. 6 pages, 3 figures, based on work presented at
the 2004 IEEE NTC Quantum Device Technology Workshop, accepted for
publication by IEEE transactions on Nanotechnolog
Super-Poissonian shot noise in the resonant tunneling due to coupling with a localized level
We report our studies of the shot noise spectrum in tunneling through an
interacting quantum dot when an additional single-level quantum dot without
tunnel coupling to leads is coherently side-connected to it. We show that the
zero-frequency shot noise could reach a super-Poissonian value for appropriate
ratios between dot-dot hoppings and dot-lead couplings, but the current is
independent on the hopping. Moreover, the frequency spectrum of shot noise
shows an obvious peak at the Rabi frequency, which is controllable by tuning
the dot-lead couplings.Comment: 3 pages, 3 figures, Appl. Phys. Lett.(in press
Pumped spin-current and shot noise spectra in a single quantum dot
We exploit the pumped spin-current and current noise spectra under
equilibrium condition in a single quantum dot connected to two normal leads, as
an electrical scheme for detection of the electron spin resonance (ESR) and
decoherence. We propose spin-resolved quantum rate equations with correlation
functions in Laplace-space for the analytical derivation of the zero-frequency
atuo- and cross-shot noise spectra of charge- and spin-current. Our results
show that in the strong Coulomb blockade regime, ESR-induced spin flip
generates a finite spin-current and the quantum partition noises in the absence
of net charge transport. Moreover, spin shot noise is closely related to the
magnetic Rabi frequency and decoherence and would be a sensitive tool to
measure them.Comment: 4 pages, 3 figures, to be published in Phys. Rev. Lette
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