1,534 research outputs found
A room temperature CO line list with ab initio computed intensities
Atmospheric carbon dioxide concentrations are being closely monitored by
remote sensing experiments which rely on knowing line intensities with an
uncertainty of 0.5% or better. We report a theoretical study providing
rotation-vibration line intensities substantially within the required accuracy
based on the use of a highly accurate {\it ab initio} dipole moment surface
(DMS). The theoretical model developed is used to compute CO intensities
with uncertainty estimates informed by cross comparing line lists calculated
using pairs of potential energy surfaces (PES) and DMS's of similar high
quality. This yields lines sensitivities which are utilized in reliability
analysis of our results. The final outcome is compared to recent accurate
measurements as well as the HITRAN2012 database. Transition frequencies are
obtained from effective Hamiltonian calculations to produce a comprehensive
line list covering all CO transitions below 8000 cm
and stronger than 10 cm / molecule at ~
Deformation of intrasalt beds recorded by magnetic fabrics
Funding Information Israel Science Foundation (ISF). Grant Number: 868/17 Israeli Government. Grant Number: 40706 Israel Science Foundation. Grant Number: 868/17Peer reviewedPublisher PD
Simultaneous measurement of coordinate and momentum on a von Neumann lattice
It is shown that on a finite phase plane the -coordinates and the sites
of a von Neumann lattice are conjugate to one another. This elementary result
holds when the number defining the size of the phase plane can be expressed
as a product, , with and being relatively prime.
As a consequence of this result a hitherto unknown wave function is defined
giving the probability of simultaneously measuring the momentum and coordinate
on the von Neumann lattice.Comment: Published in EPL 83 (2008) 1000
Multi-Resolution Analysis and Fractional Quantum Hall Effect: an Equivalence Result
In this paper we prove that any multi-resolution analysis of \Lc^2(\R)
produces, for some values of the filling factor, a single-electron wave
function of the lowest Landau level (LLL) which, together with its (magnetic)
translated, gives rise to an orthonormal set in the LLL. We also give the
inverse construction. Moreover, we extend this procedure to the higher Landau
levels and we discuss the analogies and the differences between this procedure
and the one previously proposed by J.-P. Antoine and the author.Comment: Submitted to Journal Mathematical Physisc
Lattice Twisting Operators and Vertex Operators in Sine-Gordon Theory in One Dimension
In one dimension, the exponential position operators introduced in a theory
of polarization are identified with the twisting operators appearing in the
Lieb-Schultz-Mattis argument, and their finite-size expectation values
measure the overlap between the unique ground state and an excited state.
Insulators are characterized by . We identify with
ground-state expectation values of vertex operators in the sine-Gordon model.
This allows an accurate detection of quantum phase transitions in the
universality classes of the Gaussian model. We apply this theory to the
half-filled extended Hubbard model and obtain agreement with the level-crossing
approach.Comment: 4 pages, 3 figure
Dynamic Localization in Quantum Wires
In the paper the dynamic localization of charged particle (electron) in a
quantum wire under the external non-uniform time-dependent electric field is
considered. The electrons are trapped in a deep 'dynamic' quantum wells which
are the result of specific features of the potential imposed on 2D electron
gas: the scale of spatial nonuniformity is much smaller then the electron mean
free path (L_1 << \bar{l}) and the frequency is much greater then \tau^{-1},
where \tau is the electron free flight time. As a result, the effect of this
field on the charged particle is in a sense equivalent to the effect of a
time-independent effective potential, that is a sequence of deep 'dynamic'
quantum wells were the elelctrons are confined. The possible consequeces of
this effect are also discussed and similarity with the classical Paul traps are
emphasized.Comment: 21 pages, 1 figur
Factorizations and Physical Representations
A Hilbert space in M dimensions is shown explicitly to accommodate
representations that reflect the prime numbers decomposition of M.
Representations that exhibit the factorization of M into two relatively prime
numbers: the kq representation (J. Zak, Phys. Today, {\bf 23} (2), 51 (1970)),
and related representations termed representations (together with
their conjugates) are analysed, as well as a representation that exhibits the
complete factorization of M. In this latter representation each quantum number
varies in a subspace that is associated with one of the prime numbers that make
up M
Wave-packet dynamics in slowly perturbed crystals: Gradient corrections and Berry-phase effects
We present a unified theory for wave-packet dynamics of electrons in crystals
subject to perturbations varying slowly in space and time. We derive the
wave-packet energy up to the first order gradient correction and obtain all
kinds of Berry-phase terms for the semiclassical dynamics and the quantization
rule. For electromagnetic perturbations, we recover the orbital magnetization
energy and the anomalous velocity purely within a single-band picture without
invoking inter-band couplings. For deformations in crystals, besides a
deformation potential, we obtain a Berry-phase term in the Lagrangian due to
lattice tracking, which gives rise to new terms in the expressions for the
wave-packet velocity and the semiclassical force. For multiple-valued
displacement fields surrounding dislocations, this term manifests as a Berry
phase, which we show to be proportional to the Burgers vector around each
dislocation.Comment: 12 pages, RevTe
Finite-dimensional Schwinger basis, deformed symmetries, Wigner function, and an algebraic approach to quantum phase
Schwinger's finite (D) dimensional periodic Hilbert space representations are
studied on the toroidal lattice {\ee Z}_{D} \times {\ee Z}_{D} with specific
emphasis on the deformed oscillator subalgebras and the generalized
representations of the Wigner function. These subalgebras are shown to be
admissible endowed with the non-negative norm of Hilbert space vectors. Hence,
they provide the desired canonical basis for the algebraic formulation of the
quantum phase problem. Certain equivalence classes in the space of labels are
identified within each subalgebra, and connections with area-preserving
canonical transformations are examined. The generalized representations of the
Wigner function are examined in the finite-dimensional cyclic Schwinger basis.
These representations are shown to conform to all fundamental conditions of the
generalized phase space Wigner distribution. As a specific application of the
Schwinger basis, the number-phase unitary operator pair in {\ee Z}_{D} \times
{\ee Z}_{D} is studied and, based on the admissibility of the underlying
q-oscillator subalgebra, an {\it algebraic} approach to the unitary quantum
phase operator is established. This being the focus of this work, connections
with the Susskind-Glogower- Carruthers-Nieto phase operator formalism as well
as standard action-angle Wigner function formalisms are examined in the
infinite-period limit. The concept of continuously shifted Fock basis is
introduced to facilitate the Fock space representations of the Wigner function.Comment: 19 pages, no figure
Orthogonal localized wave functions of an electron in a magnetic field
We prove the existence of a set of two-scale magnetic Wannier orbitals
w_{m,n}(r) on the infinite plane. The quantum numbers of these states are the
positions {m,n} of their centers which form a von Neumann lattice. Function
w_{00}localized at the origin has a nearly Gaussian shape of
exp(-r^2/4l^2)/sqrt(2Pi) for r < sqrt(2Pi)l,where l is the magnetic length.
This region makes a dominating contribution to the normalization integral.
Outside this region function, w_{00}(r) is small, oscillates, and falls off
with the Thouless critical exponent for magnetic orbitals, r^(-2). These
functions form a convenient basis for many electron problems.Comment: RevTex, 18 pages, 5 ps fi
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