14,785 research outputs found
Difference of optical conductivity between one- and two-dimensional doped nickelates
We study the optical conductivity in doped nickelates, and find the dramatic
difference of the spectrum in the gap (\alt4 eV) between one- (1D)
and two-dimensional (2D) nickelates. The difference is shown to be caused by
the dependence of hopping integral on dimensionality. The theoretical results
explain consistently the experimental data in 1D and
2D nickelates, YCaBaNiO and LaSrNiO,
respectively. The relation between the spectrum in the X-ray aborption
experiments and the optical conductivity in LaSrNiO is
discussed.Comment: RevTeX, 4 pages, 4 figure
Black hole thermodynamics and modified GUP consistent with doubly special relativity
We study the black hole thermodynamics and obtain the correction terms for
temperature, entropy, and heat capacity of the Schwarzschild black hole,
resulting from the commutation relations in the framework of {\it Modified
Generalized Uncertainty Principle} suggested by {\it Doubly Special
Relativity}.Comment: 13 pages, 6 figures, minor revision, references adde
Strong-field spatial interference in a tailored electromagnetic bath
Light scattered by a regular structure of atoms can exhibit interference
signatures, similar to the classical double-slit. These first-order
interferences, however, vanish for strong light intensities, restricting
potential applications. Here, we show how to overcome these limitations to
quantum interference in strong fields. First, we recover the first-order
interference in strong fields via a tailored electromagnetic bath with a
suitable frequency dependence. At strong driving, the optical properties for
different spectral bands are distinct, thus extending the set of observables.
We further show that for a two-photon detector as, e.g., in lithography,
increasing the field intensity leads to twice the spatial resolution of the
second-order interference pattern compared to the weak-field case.Comment: final versio
Spin-Orbit Coupling and Ion Displacements in Multiferroic TbMnO3
The electronic and magnetic properties of TbMnO3 leading to its ferroelectric
(FE) polarization were investigated on the basis of relativistic density
functional theory (DFT) calculations. In agreement with experiment, we show
that the spin-spiral plane of TbMnO3 can be either the bc- or ab-plane, but not
the ac-plane. As for the mechanism of FE polarization, our work reveals that
the "pure electronic" model by Katsura, Nagaosa and Balatsky (KNB) is
inadequate in predicting the absolute direction of FE polarization. For the
ab-plane spin-spiral state of TbMnO3, the direction of FE polarization
predicted by the KNB model is opposite to that predicted by DFT calculations.
In determining the magnitude and the absolute direction of FE polarization in
spin-spiral states, it is found crucial to consider the displacements of the
ions from their ecntrosymmetric positions
Nonlocal Gate Of Quantum Network Via Cavity Quantum Electrodynamics
We propose an experimentally feasible scheme to realize the nonlocal gate
between two different quantum network nodes. With an entanglement-qubit (ebit)
acts as a quantum channel, our scheme is resistive to actual environment noise
and can get high fidelity in current cavity quantum electrodynamics (C-QED)
system.Comment: 5 pages, 3 figures, 1 tabl
General Approach to Functional Forms for the Exponential Quadratic Operators in Coordinate-Momentum Space
In a recent paper [Nieto M M 1996 Quantum and Semiclassical Optics, 8 1061;
quant-ph/9605032], the one dimensional squeezed and harmonic oscillator
time-displacement operators were reordered in coordinate-momentum space. In
this paper, we give a general approach for reordering multi-dimensional
exponential quadratic operator(EQO) in coordinate-momentum space. An explicit
computational formula is provided and applied to the single mode and
double-mode EQO through the squeezed operator and the time displacement
operator of the harmonic oscillator.Comment: To appear in J. Phys. A: Mathematics and Genera
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