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81.
Andreas?Krug Sandro?Wimberger Andreas?BuchleitnerEmail author 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,26(1):21-26
We establish a close quantitative analogy between the excitation and ionization process of highly excited one electron Rydberg states under microwave driving and charge transport across disordered 1D lattices. Our results open a new arena for Anderson localization -- a disorder induced effect -- in a large class of perfectly deterministic, decaying atomic systems.Received: 15 November 2002, Published online: 8 July 2003PACS:
32.80.Rm Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states) - 05.45.Mt Quantum chaos; semiclassical methods - 72.15.Rn Localization effects (Anderson or weak localization) 相似文献
82.
ESR measurements are reported for the quasi-two-dimensional honeycomb antiferromagnet BaNi2V2O8. Planar anisotropic properties are confirmed by angular dependent investigations of resonance field and linewidth. The divergence of the temperature-dependent linewidth on approaching T(N) from above is described in terms of the Kosterlitz-Thouless transition, the critical behavior close to long-range magnetic order, and the 2D Heisenberg antiferromagnet. We provide arguments that the Kosterlitz-Thouless scenario is compatible with the observed critical exponent and suggest BaNi2V2O8 is a weakly anisotropic 2D Heisenberg antiferromagnet. 相似文献
83.
Dürr AC Schreiber F Ritley KA Kruppa V Krug J Dosch H Struth B 《Physical review letters》2003,90(1):016104
The scaling exponents alpha, beta, and 1/z in thin films of the organic molecule diindenoperylene deposited on SiO2 under UHV conditions are determined. Atomic-force microscopy, x-ray reflectivity, and diffuse x-ray scattering were employed. The surface width displays power law scaling over more than 2 orders of magnitude in film thickness. We obtained alpha = 0.684+/-0.06, beta = 0.748+/-0.05, and 1/zeta = 0.92+/-0.20. The derived exponents point to an unusually rapid growth of vertical roughness and lateral correlations. We suggest that they could be related to lateral inhomogeneities arising from the formation of grain boundaries between tilt domains in the early stages of growth. 相似文献
84.
Fichtl R Tsurkan V Lunkenheimer P Hemberger J Fritsch V von Nidda HA Scheidt EW Loidl A 《Physical review letters》2005,94(2):027601
Low-temperature specific heat measurements and dielectric spectroscopy have been performed on polycrystalline and single-crystalline FeCr2S4, the single crystals showing a transition into a low-temperature orbital glass phase. The freezing of the orbital moments is revealed by a glasslike specific heat anomaly and by a clear relaxational behavior of the dielectric permittivity, exhibiting several hallmark features of glassy dynamics. The orbital relaxation dynamics continuously slows down over six decades in time, before at the lowest temperatures the glass transition becomes suppressed by quantum tunneling. 相似文献
85.
A simple, fast method for the determination of boron in plant extracts is described. The method utilizes injection of 1.0 ml of an acid plant digest into a 0.1 M hydrochloric acid stream, with further addition of a buffer—masking solution and azomethine-H as the colour-forming reagent. Effects of pH, kinetics of colour reaction development, sample volume, reagent composition and interferences are described. The proposed method allows the analysis of plant extracts with boron contents in the range 0.1–6.0 ppm at a rate of 60 determinations per hour, with a reagent consumption of 2 mg of azomethine-H per sample. The precision is good (r.s.d. < 1%) and the results agree with those obtained by the curcumin method. 相似文献
86.
87.
88.
Detlef Krug 《Thermochimica Acta》1977,20(1):53-64
With solid state reactions it turns out more and more, that it is possible to accept the classical Arrhenius equation in heterogeneous kinetics. For that purpose the contents of the most important terms preexponential factor, energy of activation and the reactions exponent had to be formulated anew.In the second part of the lecture it will be introduce to the evaluation of kinetic measurements with progressive guidance of temperature, especially by use of smaller table computers. With this, the new “Gitty” - method is presented, with which the kinetic dates can be obtained with the help of a plotter. 相似文献
89.
Ch. Kegler N. Büttgen H.-A. Krug von Nidda A. Krimmel L. Svistov B.I. Kochelaev A. Loidl A. Prokofiev W. Aßmus 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,22(3):321-326
EPR and 7Li NMR measurements were performed in the distorted inverse spinel V(LiCu)O4 down to 1.5 K. Anisotropy effects on magnetic resonance spectra due to the Jahn-Teller distortion of the oxygen octahedra
surrounding the copper ions are discussed. The estimation of the spin-spin interactions deduced from the EPR-relaxation rate
Δ
H reveals a situation comparable to the prototypical one-dimensional S
= 1/2 Heisenberg antiferromagnet CuGeO3. Approaching three-dimensional antiferromagnetic order ( T
N
≈ 2 K) from above, both magnetic relaxation rates, Δ
H
EPR
and
7
(1/
T
1
), respectively, exhibit nearly the same critical divergence reminding to the onset of three-dimensional order in two-dimensional
layered systems.
Received 22 January 2001 and Received in final form 6 May 2001 相似文献
90.
I. V. Yatsyk D. V. Mamedov I. I. Fazlizhanov T. P. Gavrilova R. M. Eremina N. V. Andreev V. I. Chichkov Ya. M. Mukovskii H. -A. Krug von Nidda A. Loidl 《JETP Letters》2012,96(6):416-420
Electronic paramagnetic resonance (EPR) spectra of a GdMnO3 single crystal and GdMnO3/LaAlO3 thin film have been measured at X- and Q-band frequencies in the temperature range from 4.2 to 300 K. It is found that the EPR spectrum of a GdMnO3 single crystal consists of only one broad exchange-narrowed line. Unusual magnetism is observed at the interface between the GdMnO3 thin film and LaAlO3 substrate, where it is possible to see the fine structure of the EPR spectrum for a Gd3+ ion. The parameters characterizing the fine structure related to the Gd3+ ion in the GdMnO3 film deposited onto the LaAlO3 substrate are determined. 相似文献