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1.
We consider a magnetic Laplacian −Δ
A
= (id + A)* (id + A) on a non-compact hyperbolic surface M with finite area. A is a real one-form and the magnetic field dA is constant in each cusp. When the harmonic component of A satisfies some quantified condition, the spectrum of −Δ
A
is discrete. In this case, we prove that the counting function of the eigenvalues of −Δ
A
satisfies the classical Weyl formula, even when dA=0. 相似文献
2.
Pablo A. Ferrari Beat M. Niederhauser Eugene A. Pechersky 《Journal of statistical physics》2007,128(5):1159-1176
We consider the Harmonic crystal, a measure on
with Hamiltonian H(x)=∑
i,j
J
i,j
(x(i)−x(j))2+h∑
i
(x(i)−d(i))2, where x, d are configurations, x(i), d(i)∈ℝ, i,j∈ℤ
d
. The configuration d is given and considered as observations. The ‘couplings’ J
i,j
are finite range. We use a version of the harness process to explicitly construct the unique infinite volume measure at finite
temperature and to find the unique ground state configuration m corresponding to the Hamiltonian. 相似文献
3.
We show that the classical Nambu-Goto string inD dimensions admits Poincaré invariance ind dimensions (d⩽D) if (i)d − 2 of the transverse co-ordinatesx
i are periodic and the rest quasi-periodic involving a real orthogonal matrix with (D − d) (D − d − 1)/2 free parameters, or if (ii)d − 2 ofx
i obey Neumann and the rest obey a boundary condition involvingN free parameters, whereN=(D − d)2/2 ifD − d is even, andN=[(D − d)2 − 1]/2 ifD − d is odd. 相似文献
4.
5.
Barnes M. Fraser M. M. Hajigeorgiou P. G. Merer A. J. 《Journal of Molecular Spectroscopy》1995,170(2)
The orange system of FeO has been reinvestigated using low-temperature molecular beam laser-induced fluorescence spectra, obtained by supersonic jet cooling. Two new weak bands have been found, and analyses of some of the previously known bands extended. Measurements of the 54Fe-56Fe isotope shifts have been made for most of the bands, and the hyperfine structure of the low-J lines has been recorded for two of the strongest bands of 57FeO. The isotope shifts are consistent with the presence of two 5Δi-5Δi transitions lying within 1000 cm−1; the origins of the Ω = 4 spin components lie at 5583 and 6110 Å, respectively. The hyperfine patterns and the spin-orbit structure indicate that the upper state electron configurations are (3dδ)3 (3dπ)2 (3dσ)1, (D5Δi, 5583 Å) and O(2pπ)3 (4sσ)1 (3dδ)3(3dπ)3, (D′5Δi, 6110 Å). The bond length in the D′ state (r0 = 1.654 Å) has been obtained from a deperturbation of the 6110 Å band; it is only 0.035 Å longer than in the ground state, which indicates that electron promotion between the two π orbitals, nominally O(2pπ) and Fe(3dπ), has only a small effect on the strength of the bonding. The new isotope data still do not clarify the vibrational assignments of the higher levels, which are disorganized by extensive electronic perturbations. 相似文献
6.
V. D. Borman M. A. Pushkin V. N. Tronin V. I. Troyan 《Journal of Experimental and Theoretical Physics》2010,110(6):1005-1025
The electronic properties of nanoclusters of transition (Ni, Co, Cr) and noble (Au, Cu) metals deposited on the surface of
highly oriented pyrolytic graphite (HOPG) are studied using the method of X-ray photoelectron spectroscopy. The laws of variation
of a change ΔE
b in the binding energies of core-level electrons in the initial (ΔE
i) and final (ΔE
f) states of atoms in nanoclusters, the intrinsic widths γ of photoelectron lines, and their singularity indices α as functions
of the metal cluster size d are determined. A qualitative difference in behavior of the ΔE
i(d) and α(d) values in metals of the two groups (Ni, Cr versus Co, Cu) is found. The values of the final-state energy (ΔE
f < 0) and the line width (Δγ > 0) in the clusters of all metals studied vary in a similar manner. It is shown that a significant
contribution to E
i is due to a transfer of the valence-shell electrons at the cluster-substrate interface, which is caused by the contact potential
difference. The value of an uncompensated charge per nanocluster is determined as a function of the cluster size and the number
of atoms in the cluster. The behavior of ΔE
f(d) is controlled by the Coulomb energy of a charged cluster and by a decrease in the efficiency of electron screening, which
is different in the metals studied. The broadening of photoelectron lines is determined by a spread of the cluster sizes and
by lower electron screening in the final Fermi system. An asymmetry of the core-level electron spectra of nanoclusters can
be explained using notions about the electron-hole pair excitation near the Fermi level. The effect of the structure of the
density of electron states in the d band of transition metals on the asymmetry of photoelectron lines is considered and it is concluded that this structure near
the Fermi level qualitatively changes with a decrease in the nanocluster size. The obtained results indicate that the behavior
of the electron subsystem of clusters of the d-metals in a size range of 2–10 nm under consideration is close to the behavior of a normal Fermi system. 相似文献
7.
A. Bahraminasab M. Sadegh Movahed S. D. Nasiri A. A. Masoudi Muhammad Sahimi 《Journal of statistical physics》2006,124(6):1471-1490
We carry out an exact analysis of the average frequency ν+
αxi
in the direction x
i
of positiveslope crossing of a given level α such that, h(x, t) − = α, of growing surfaces in spatial dimension d. Here, h(x, t) is the surface height at time t, and is its mean value. We analyze the problem when the surface growth dynamics is governed by the Kardar-Parisi-Zhang (KPZ) equation without surface tension, in the time regime prior to appearance of cusp singularities (sharp valleys), as well as in the random deposition (RD) model. The total number N
+ of such level-crossings with positive slope in all the directions is then shown to scale with time as t
d/2 for both the KPZ equation and the RD model.
PACS number(s): 52.75.Rx, 68.35.Ct 相似文献
8.
9.
N. A. Inogamov V. V. Zhakhovsky S. I. Ashitkov V. A. Khokhlov V. V. Shepelev P. S. Komarov A. V. Ovchinnikov D. S. Sitnikov Yu. V. Petrov M. B. Agranat S. I. Anisimov V. E. Fortov 《等离子体物理论文集》2011,51(4):367-374
We combine theoretical and experimental methods to study the processes induced by fast laser heating of metal foils. These processes reveal themselves through motion of frontal (irradiated) and rear‐side foil boundaries. The irradiated targets are 0.3‐2 micron thick aluminum foils deposited on much thicker (150 microns) glass plate. The instant boundary positions is measured by pump‐probe technique having ∼40‐150 fs time and ∼1 nm spatial resolutions. Ultrashort laser pulse transforms a frontal surface layer with thickness dT into two‐temperature (Te ≫ Ti) warm dense matter state. Its quantitative characteristics including its thickness are defined by poorly known coefficients of electron‐ion energy exchange α and electron heat conductivity κ. Fast laser heating rises pressure in the dT‐layer and therefore produce acoustic waves. Propagation and reflection from the frontal and rear boundaries of these waves causes the displacement Δx (t) of boundary positions. Pressure wave profiles, and hence functions Δx (t), depend on thickness dT. This is why the experimental detection of Δx (t) opens a way to accurate evaluation of the coefficients α and κ (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.
ABSTRACTThe spin-Hamiltonian parameters (g factors gi, hyperfine structure constants Ai (95Mo5+) and Ai (97Mo5+), i?=?// and ⊥) assigned to the tetragonal Mo5+ (4d1) tetrahedral center in α-ZnMoO4 crystal caused by a Mo6+(1) ion trapping an electron after x-ray irradiation are calculated from the high-order perturbation formulas resting on the two-mechanism model. The model takes account of both the effects of crystal-field (CF) mechanism concerning the CF excited states in the CF theory and that of the charge-transfer (CT) mechanism related to CT excited states. The calculated results are reasonably consistent with the experimental values, confirming this assignment (or defect model). The calculations also indicate that the effect of CT mechanism cannot be neglected. The defect structure (particularly, the angular distortion) and signs of constants Ai (95Mo5+) and Ai (97Mo5+) of this Mo5+ defect center are also decided from the calculations. The outcomes are discussed. 相似文献
11.
The generators of the Lie algebra of the symplectic groupsp(2n, R) are, recurrently, realized by means of polynomials in the quantum canonical variablesp
i andq
i. These realizations are skew-Hermitian, the Casimir operators are realized by constant multiples of identity elements, and, depending on the number of the canonical pairs used, they depend ond, d=1, 2, ...,n free real parameters. 相似文献
12.
We present a deposition and evaporation model for surface growth under a solid-on-solid constraint. We generalize the Ising-spin representation of a two-dimensional surface by Blöte and Hilhorst to ad-dimensional surface of a (d+1)-dimensional hypercubic lattice. The allowed surface configurations correspond to the (degenerate) ground states of a chirald-state Potts model. We describe a vectorized multisite-coding implementation for the corresponding kinetic Potts-spin model ford=2 andd=3. For thed=2 equilibrium surface our simulation results show excellent agreement with an exact analysis. 相似文献
13.
A generalized Weyl—Wigner quantization scheme unifying P-Q and Q-P ordering and Weyl ordering of operators
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By extending the usual Wigner operator to the s-parameterized one as 1/4π2 integral (dyduexp [iu(q-Q)+iy(p-P)+is/2yu]) from n=- ∞ to ∞ with s beng a,real parameter,we propose a generalized Weyl quantization scheme which accompanies a new generalized s-parameterized ordering rule.This rule recovers P-Q ordering,Q-P ordering,and Weyl ordering of operators in s = 1,1,0 respectively.Hence it differs from the Cahill-Glaubers’ ordering rule which unifies normal ordering,antinormal ordering,and Weyl ordering.We also show that in this scheme the s-parameter plays the role of correlation between two quadratures Q and P.The formula that can rearrange a given operator into its new s-parameterized ordering is presented. 相似文献
14.
Tunneling conductance in quantum wire/insulator/dx2 -y2 + idxy mixed wave superconductor junctions
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Using the extended Blonder-Tinkham-Klapwijk (BTK) theory, this paper calculates the tunnelling conductance in quantum wire/insulator/dx2-y2 + idxy mixed wave superconductor (q/I/dx2-y2 + idxy) junctions. That is different from the case in d- and p-wave superconductor junctions. When the angle α between a-axis of the dx2-y2 wave superconductor and the interface normal is π/4, there follows a rather distinctive tunnelling conductance. The zero-bias conductance peak (ZBCP) may or may not appear in the tunnelling conductance. Both the interface potential z and the quasi-particle lifetime factor Γ are smaller, there is no ZBCP. Otherwise, the ZBCP will appear. The position of bias conductance peak (BCP) depends strongly on the amplitude ratio of two components for dx2-y2 + idxy mixed wave. The low and narrow ZBCP may coexist with the BCP in the tunnelling conductance. Using those features in the tunnelling conductance of q/I/dx2-y2 + idxy junctions, it can distinguish dx2-y2 + idxy mixed wave superconductor from d- and p-wave one. 相似文献
15.
Mathew D. Penrose 《Journal of statistical physics》2008,131(2):247-268
In ballistic deposition (BD), (d+1)-dimensional particles fall sequentially at random towards an initially flat, large but bounded d-dimensional surface, and each particle sticks to the first point of contact. For both lattice and continuum BD, a law of
large numbers in the thermodynamic limit establishes convergence of the mean height and surface width (sample standard deviation
of the height) of the interface to constants h(t) and w(t), respectively, depending on time t. We show that h(t) is asymptotically linear in t, while (w(t))2 grows at least logarithmically in t when d=1. We use duality results showing that w(t) can be interpreted as the standard deviation of the height for deposition onto a surface growing from a single point. 相似文献
16.
We present a study, within a mean-field approach, of the kinetics of a mixed ferrimagnetic model on a square lattice in which two interpenetrating square sublattices have spins that can take two values, , alternated with spins that can take the four values, . We use the Glauber-type stochastic dynamics to describe the time evolution of the system with a crystal-field interaction in the presence of a time-dependent oscillating external magnetic field. The nature (continuous and discontinuous) of transition is characterized by studying the thermal behaviors of average order parameters in a period. The dynamic phase transition points are obtained and the phase diagrams are presented in the reduced magnetic field amplitude (h) and reduced temperature (T) plane, and in the reduced temperature and interaction parameter planes, namely in the (h, T) and (d, T) planes, d is the reduced crystal-field interaction. The phase diagrams always exhibit a tricritical point in (h, T) plane, but do not exhibit in the (d, T) plane for low values of h. The dynamic multicritical point or dynamic critical end point exist in the (d, T) plane for low values of h. Moreover, phase diagrams contain paramagnetic (p), ferromagnetic (f), ferrimagnetic (i) phases, two coexistence or mixed phase regions, (f+p) and (i+p), that strongly depend on interaction parameters. 相似文献
17.
Richard Kerner 《Letters in Mathematical Physics》1996,36(4):441-454
We present a possible generalization of the exterior differential calculus, based on the operator d such that d3=0, but d20. The entities dx
i
and d2
x
k
generate an associative algebra; we shall suppose that the products dx
i
dx
k
are independent of dx
k
dx
i
, while theternary products will satisfy the relation: dx
i
dx
k
dx
m
=jdx
k
dx
m
dx
i
=j
2dx
m
dx
m
dx
i
dx
k
, complemented by the relation dx
i
d2
x
k
=jd2
x
k
dx
i
, withj:=e2i/3.We shall attribute grade 1 to the differentials dx
i
and grade 2 to the second differentials d2
x
k
; under the associative multiplication law the grades add up modulo 3.We show how the notion ofcovariant derivation can be generalized with a 1-formA so thatD:=d+A, and we give the expression in local coordinates of thecurvature 3-form defined as :=d2
A+d(A
2)+AdA+A
3.Finally, the introduction of notions of a scalar product and integration of theZ
3-graded exterior forms enables us to define the variational principle and to derive the differential equations satisfied by the 3-form . The Lagrangian obtained in this way contains the invariants of the ordinary gauge field tensorF
ik
and its covariant derivativesD
i
F
km
. 相似文献
18.
Q. H. Liu 《International Journal of Theoretical Physics》2006,45(11):2137-2142
When the motion of a particle is constrained on the two-dimensional surface, excess terms exist in usual kinetic energy 1/(2m)∑ p
i
2 with hermitian form of Cartesian momentum p
i
(i = 1,2,3), and the operator ordering should be taken into account in the kinetic energy which turns out to be 1/(2m)∑ (1/f
i
)p
i
f
i
p
i
where the functions f
i
are dummy factors in classical mechanics and nontrivial in quantum mechanics. The existence of non-trivial f
i
shows the universality of this constraint induced operator ordering in quantum kinetic energy operator for the constraint systems. 相似文献
19.
X. Wang Y. P. Xiao T. G. Liu M. M. Lai J. Rao 《International Journal of Theoretical Physics》2006,45(12):2464-2470
When the motion of a particle is constrained on the two-dimensional surface, excess terms exist in usual kinetic energy 1/(2μ) ∑ p
i
2 with hermitian form of Cartesian momentum p
i
(i = 1,2,3), and the operator ordering should be taken into account in the kinetic energy which turns out to be 1/(2μ) ∑ (1/f
i
)p
i
f
i
p
i
where the functions f
i
are dummy factors in classical mechanics and nontrivial in quantum mechanics. In this article, the explicit forms of the dummy functions f
i
for quantum motion on some 2D surfaces of revolution of spherical topology are given.
PACS numbers: 03.65.-w Quantum mechanics, 04.60.Ds Canonical quantization. 相似文献
20.
We develop a position space renormalisation group (RG) method to study generalised depinning transition in two-dimensional Ising models. The treatment encompasses (i) the original model for depinning invented by Abraham, (ii) generalised depinning model, (iii) nonuniversal behaviour near the internal line of defects and (iv) surface and interface behaviour. The phase diagrams and the thermodynamic functions over the whole range of temperatures are obtained. The agreement with exact results (when available) is quite satisfactory. 相似文献