Anomalous Long Time Tail Behavior of Spin-Spin Correlation in the Normal State ofTl2Ba2CuOy

1994 ◽  
Vol 73 (1) ◽  
pp. 197-200 ◽  
Author(s):  
Shinsaku Kambe ◽  
Hiroshi Yasuoka ◽  
Akihiko Hayashi ◽  
Yutaka Ueda
Keyword(s):  
Normal State ◽  
Spin Correlation ◽  
Tail Behavior ◽  
Long Time

scholarly journals LONG-TIME RELAXATION ON SPIN LATTICE AS A MANIFESTATION OF CHAOTIC DYNAMICS

2004 ◽  
Vol 18 (08) ◽  
pp. 1119-1159 ◽  
Author(s):  
BORIS V. FINE
Keyword(s):  
Correlation Functions ◽  
Time Scale ◽  
Inelastic Neutron Scattering ◽  
Spin Correlation ◽  
Inelastic Neutron ◽  
Theoretical Explanation ◽  
Characteristic Time Scale ◽  
Time Behavior ◽  
Intermediate Structure ◽  
Long Time

The long-time behavior of the infinite temperature spin correlation functions describing the free induction decay in nuclear magnetic resonance and intermediate structure factors in inelastic neutron scattering is considered. These correlation functions are defined for one-, two- and three-dimensional infinite lattices of interacting spins, both classical and quantum. It is shown that, even though the characteristic time-scale of the long-time decay of the correlation functions considered is non-Markovian, the generic functional form of this decay is either simple exponential or exponential multiplied by cosine. This work contains (i) the summary of the existing experimental and numerical evidence of the above asymptotic behavior; (ii) theoretical explanation of this behavior; and (iii) semi-empirical analysis of various factors discriminating between the monotonic and the oscillatory long-time decays. The theory is based on a fairly strong conjecture that, as a result of chaos generated by spin dynamics, a Brownian-like Markovian description can be applied to the long-time properties of ensemble average quantities on a non-Markovian time-scale. The formalism resulting from that conjecture can be described as "correlated diffusion in finite volumes."

63Cu-NMR Study in High-Tc Superconductor HgBa2Ca2Cu3O8 + δ

1996 ◽  
Vol 51 (5-6) ◽  
pp. 801-804
Author(s):  
K. Magishi ◽  
G.-q. Zheng ◽  
Y. Kitaoka ◽  
K. Asayama ◽  
K. Tokiwa ◽  
...  
Keyword(s):  
Decay Rate ◽  
Normal State ◽  
Spin Echo ◽  
Spin Correlation ◽  
Gaussian Component ◽  
Relaxation Rates ◽  
Transverse Relaxation ◽  
High Tc ◽  
High Tc Superconductor ◽  
Nmr Study

Abstract The 63Cu nuclear transverse relaxation rates have been measured in the normal state on both square and pyramidal CuO2 planes in HgBa2Ca2Cu3O8 + δ with Tc = 133K. The Gaussian component of the spin-echo decay rate, 63(1/T2G), for both sites increases with decreasing temperature, followed by a peak around T* ~ 150 K, indicating that the spin correlation becomes stronger with decreasing temperature. Also, it is found that the magnitude of 63(1/T2G) for a square site is larger than that for a pyramidal one, suggesting that the spin correlation in the square plane is stronger than that in the pyramidal one.

LT: It was a very heady, weird time—traumatic—after all those assassinations. It was extremely disturbing sometimes. PN: The motifs of travel, movement, the journey, the quest have a central place in your work. I was reminded of the way travel also figures in Jane Bowles’s fiction. She describes it as ‘a sensation that lay between suffering and enjoyment’ and she adds that for her character Lila, ‘it had a direct connection with her brother’s lies’— it’s as if the ambivalent feelings occasioned by travel have some fundamental relation to fiction. LT: In a way writing, like travel, is uncomfortable. Even if you get pleasure from it, and I do, the desire to do it also probably comes from tremendous frustration and a peculiar kind of displacement that you want to pin down. I don’t actually find travelling that enjoyable, but on the other hand I have a greater fear of stasis. I mean I have a real fear that if I sit in my apartment, for a very long time, I’ll lose any kind of perspective I have, that I really won’t be able to see my thoughts at all. They’ll simply be the wallpaper everything else is and I’ll just accept everything. My fear is that I’ll just accept all the ways in which I’m limited because I won’t any more see them as limits. You begin to recognize your limits when you’re up against the unfamiliar. PN: In Motion Sickness, you use a quotation from Julia Kristeva as an epigraph: ‘The expatriate represents, in fact, the normal state of an average citizen in this last part of the 20th century.’ Why is that notion so suggestive for you? LT: Because of issues around alienation…and the alien nation within. I was trying to turn a so-called anti-anti-travel novel [sic] into something that’s really about the place you’re in. Turning it on its head. I wanted to turn it all around and say, OK, here’s this travel business, but you can think about this differently. You can think that where you are is also not a secure place to be, and that you’re maybe feeling as uprooted as somebody who’s not in their own country. I mean, think about all the different populations in America who aren’t exactly served by that system. PN: You remember Orwell’s essay ‘Inside the whale’ on Henry Miller. He argues that expatriates always have a superficial sense of what’s going on, a limited perception of the place they’re in. LT: In England I cringe when they talk about something I’ve done as ‘expatriate’. I think Oh my God I’ve written an expat novel. There’s something really hideous about that. I think part of why I’ve done what I’ve done is an in-your-face thing. There’s a real distrust in the States of people who choose to live somewhere else. They’re losers, they can’t make it. Whatever the Romantic

2005 ◽  
pp. 51-51
Keyword(s):  
Normal State ◽  
Central Place ◽  
Julia Kristeva ◽  
The Other ◽  
Fundamental Relation ◽  
Direct Connection ◽  
Henry Miller ◽  
Long Time ◽  
Different Populations ◽  
Secure Place

scholarly journals Domain wall problem in the quantum XXZ chain and semiclassical behavior close to the isotropic point

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Grégoire Misguich ◽  
Nicolas Pavloff ◽  
Vincent Pasquier
Keyword(s):  
Domain Wall ◽  
Entanglement Entropy ◽  
Spin Correlation ◽  
Quantitative Agreement ◽  
Isotropic Point ◽  
Density Matrix Renormalization ◽  
Energy Current ◽  
Quantum Chain ◽  
Xxz Chain ◽  
Long Time

We study the dynamics of a spin-\frac{1}{2}12 XXZ chain which is initially prepared in a domain-wall state. We compare the results of time-dependent Density Matrix Renormalization Group simulations with those of an effective description in terms of a classical anisotropic Landau-Lifshitz (LL) equation. Numerous quantities are analyzed: magnetization (xx, yy and zz components), energy density, energy current, but also some spin-spin correlation functions or entanglement entropy in the quantum chain. Without any adjustable parameter a quantitative agreement is observed between the quantum and the LL problems in the long time limit, when the models are close to the isotropic point. This is explained as a consequence of energy conservation. At the isotropic point the mapping between the LL equation and the nonlinear Schrödinger equation is used to construct a variational solution capturing several aspects of the problem.

Heavy Tails of Discounted Aggregate Claims in the Continuous-Time Renewal Model

2007 ◽  
Vol 44 (02) ◽  
pp. 285-294 ◽  
Author(s):  
Qihe Tang
Keyword(s):  
Asymptotic Formula ◽  
Continuous Time ◽  
Heavy Tails ◽  
Tail Behavior ◽  
Renewal Model ◽  
Discounted Aggregate Claims ◽  
Aggregate Claims ◽  
Tail Asymptotic

We study the tail behavior of discounted aggregate claims in a continuous-time renewal model. For the case of Pareto-type claims, we establish a tail asymptotic formula, which holds uniformly in time.

200kv superconducting cryo electron microscope

1987 ◽  
Vol 45 ◽  
pp. 642-643
Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada ◽  
J. Lehman
Keyword(s):  
Electron Microscope ◽  
Structure Analysis ◽  
Organic Materials ◽  
Strong Interactions ◽  
Specimen Preparation ◽  
Great Effort ◽  
Electron Microscopic ◽  
Crystal Fields ◽  
Special Skill ◽  
Long Time

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.

A Stationary Solution of High-Energy Electron Reflection (HEER) for An Arbitrary Surface

1990 ◽  
Vol 48 (2) ◽  
pp. 374-375
Author(s):  
YIQUN MA
Keyword(s):  
Stationary Solution ◽  
High Energy ◽  
Bloch Wave ◽  
Dynamical Theory ◽  
High Energy Electron ◽  
Bulk Materials ◽  
Periodic Surface ◽  
Electron Transmission ◽  
Electron Reflection ◽  
Long Time

For a long time, the development of dynamical theory for HEER has been stagnated for several reasons. Although the Bloch wave method is powerful for the understanding of physical insights of electron diffraction, particularly electron transmission diffraction, it is not readily available for the simulation of various surface imperfection in electron reflection diffraction since it is basically a method for bulk materials and perfect surface. When the multislice method due to Cowley & Moodie is used for electron reflection, the “edge effects” stand firmly in the way of reaching a stationary solution for HEER. The multislice method due to Maksym & Beeby is valid only for an 2-D periodic surface.Now, a method for solving stationary solution of HEER for an arbitrary surface is available, which is called the Edge Patching method in Multislice-Only mode (the EPMO method). The analytical basis for this method can be attributed to two important characters of HEER: 1) 2-D dependence of the wave fields and 2) the Picard iteractionlike character of multislice calculation due to Cowley and Moodie in the Bragg case.

Direct imaging of charge transfer

1996 ◽  
Vol 54 ◽  
pp. 680-681
Author(s):  
Yimei Zhu ◽  
J. Tafto
Keyword(s):  
Charge Transfer ◽  
Electron Diffraction ◽  
Scattering Amplitude ◽  
High Temperature Superconductors ◽  
Charge Carriers ◽  
Image Charge ◽  
Net Charge ◽  
Long Time ◽  
Electron Holes ◽  
First Time

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.

Microstructural characterization of plasma-processed Ti-Al metal matrix composites

1989 ◽  
Vol 47 ◽  
pp. 552-553
Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Plasma Processing ◽  
Microstructural Characterization ◽  
High Temperature Strength ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
Long Time ◽  
Strength And Stiffness ◽  
Intermetallic Matrix Composites

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.

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