8,892 research outputs found
Stark-Effect Scattering in Rough Quantum Wells
A scattering mechanism stemming from the Stark-shift of energy levels by
electric fields in semiconductor quantum wells is identified. This scattering
mechanism feeds off interface roughness and electric fields, and modifies the
well known 'sixth-power' law of electron mobility degradation. This work first
treats Stark-effect scattering in rough quantum wells as a perturbation for
small electric fields, and then directly absorbs it into the Hamiltonian for
large fields. The major result is the existence of a window of quantum well
widths for which the combined roughness scattering is minimum. Carrier
scattering and mobility degradation in wide quantum wells are thus expected to
be equally severe as in narrow wells due to Stark-effect scattering in electric
fields.Comment: 4 pages, 2 figures with png forma
Enhanced Di-Higgs Production in the Two Higgs Doublet Model
We show that the rate for di-Higgs production at the LHC can be enhanced by a
factor as large as 25 compared to the Standard Model value in the two Higgs
doublet model while being consistent with the known properties of the observed
Higgs boson . There are correlated modifications in and
resonant production rates, which can serve as tests of this model. Our
framework treats both Higgs doublets on equal footing, each with comparable
Yukawa couplings to fermions. The Cheng-Sher ansatz for multi-Higgs doublet
model is shown to be strongly disfavored by current experiments. We propose a
new ansatz for the Yukawa couplings of the Higgs doublets is proposed,
where , with
being order one coefficients, the mass of fermion and
the electroweak vacuum expectation value. Such a pattern of couplings can
explain the observed features of fermion masses and mixings and satisfies all
flavor violation constraints arising from the exchange of neutral Higgs bosons.
The rate for decay and new contributions to CP
violation in mixing are predicted to be close to the
experimental limits.Comment: 47 pages, 15 figures, published version in JHE
Non-Hermitian Quantum Mechanics with Minimal Length Uncertainty
We study non-Hermitian quantum mechanics in the presence of a minimal length.
In particular we obtain exact solutions of a non-Hermitian displaced harmonic
oscillator and the Swanson model with minimal length uncertainty. The spectrum
in both the cases are found to be real. It is also shown that the models are
pseudo-Hermitian and the metric operator is found explicitly in both the
cases
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