Elizabeth Engel nee Benjamin-Rasmussen with her daughter Dorel Hall nee Engel in Elizabeth's home; Silver Springs, Maryland Portraits Family

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Applicability of the van der Pauw-Hall measurement technique to implanted samples

The application of the van der Pauw-Hall measurement technique to implanted samples in which the mobility varies with depth has still not been fully justified. A proof that the technique is in fact applicable in this situation is given. Journal of Applied Physics is copyrighted by The American Institute of Physics.

Deutsch-Boehm Family collection 1834-1938 Bulk: 1834-1892

The collection holds original official documents pertaining to the ancestors of Hermann Deutsch, such as his father, Hugo Deutsch, and his grandfather, Simon Deutsch, and the last will and testament of Abraham Nathan Meyer, great-grandfather of Hermann Deutsch. Also included are documents for Hermann Boehm. There is a printed obituary by Hugo Preuss for Hugo Deutsch and the copy of a 1938 document, declaring the end of the Simon Boehm company.

The Gift of a Sage. Life and Wisdom of Rabbi Dr. Friedrich Hillel 1892- 1974

Manuscript by Erwin Tramer: "The Gift of a Sage. Life and Wisdom of Rabbi Dr. Friedrich Hillel". Biography of an orthodox rabbi (1865-1928), born in Wisnitz, Austrian Galicia, and who served in Leipnik, Czechoslovakia.

AC conductivity of a quantum Hall line junction

We present a microscopic model for calculating the AC conductivity of a finite length line junction made up of two counter-or co-propagating single mode quantum Hall edges with possibly different filling fractions. The effect of density-density interactions and a local tunneling conductance (sigma) between the two edges is considered. Assuming that sigma is independent of the frequency omega, we derive expressions for the AC conductivity as a function of omega, the length of the line junction and other parameters of the system. We reproduce the results of Sen and Agarwal (2008 Phys. Rev. B 78 085430) in the DC limit (omega -> 0), and generalize those results for an interacting system. As a function of omega, the AC conductivity shows significant oscillations if sigma is small; the oscillations become less prominent as sigma increases. A renormalization group analysis shows that the system may be in a metallic or an insulating phase depending on the strength of the interactions. We discuss the experimental implications of this for the behavior of the AC conductivity at low temperatures.

Aus meinem Leben 1899-1918

The memoir was written between 1899 and 1918. Family history going back to the early 18th century. Recollection of the author's childhood in Hildesheim. Moritz was the youngest child of Joseph and Bena Guedemann. Early death of his father in 1847. Moritz attended the Jewish elementary school prior to the age of five. In 1843 he was enrolled in the episcopal "Josephinum Gymnasium", where he was the only Jewish student in the entire school. He had friendly relationships with students and teachers and was not confronted with antisemitism during his school years. Moritz Guedemann graduated in 1853 and enrolled in the newly established Jewish Theological Seminary in Breslau. Description of teachers and colleagues in the seminary. Doctorate in 1858 and continuation of rabbinic studies. Occasional invitation to preach at the high holidays in Berlin, where Moritz got acquainted with the famous rabbi Dr. Michael Sachs. Position as a rabbi in Magdeburg in 1862. Small publications of studies in Jewish history. Engagement with Fanny Spiegel. In 1863 Moritz and Fanny Guedemann got married. Offer to succeed rabbi Michael Sachs in Berlin. Division and intrigues in the Jewish community and withdrawing from the position. Invitation to give a sermon in Vienna. In 1866 Moritz Guedemann was nominated to succeed rabbi Mannheimer at the Leopoldstadt synagogue in Vienna. Austro-Prussian war and defeat of Austria in Koeniggraetz. Initial difficulties and cultural differences. Criticism toward his orthodox conduct in the Vienna Jewish press ("Neuzeit"). Cultural life in Vienna. Welfare institutions and philanthropists. Difference within the Jewish community. Crash of the stock exchange and rise of antisemitism. Publication of sermons and studies in Jewish history. In 1891 Max Guedemann became chief rabbi of Vienna. Speeches against antisemitism and blood libel trials. He was awarded with the title "Ritter" of the Kaiser Franz Joseph order for these achievements. Death of his wife in

Michaelson family papers, undated, 1892-1920, 1943-1944, 1965, 1992, 1994, 1999-2000.

The Michaelson family papers include early family correspondence, documents, and ephemera; genealogical research conducted by Ms. Appleby, Anna’s granddaughter; copies of New York City marriage certificates kept by Louis B. Michaelson, Rabbi, between 1906-1907; and Anna Michaelson’s copies of original birth records that she kept as midwife in the Lower East Side in New York City between 1892-1916.

Lipperode; Jewish Community Collection 1830-1939

Community record book 1846-1939; documents; business contracts; papers of individuals.

Program for July 4th celebration at Tamany Hall

Program for July 4th celebration at Tammany Hall, 8 pages.

Tetragonal bismuth bilayer: A stable and robust quantum spin hall insulator

Topological insulators (TIs) exhibit novel physics with great promise for new devices, but considerable challenges remain to identify TIs with high structural stability and large nontrivial band gap suitable for practical applications. Here we predict by first-principles calculations a two-dimensional (2D) TI, also known as a quantum spin Hall (QSH) insulator, in a tetragonal bismuth bilayer (TB-Bi) structure that is dynamically and thermally stable based on phonon calculations and finite-temperature molecular dynamics simulations. Density functional theory and tight-binding calculations reveal a band inversion among the Bi-p orbits driven by the strong intrinsic spin-orbit coupling, producing a large nontrivial band gap, which can be effectively tuned by moderate strains. The helical gapless edge states exhibit a linear dispersion with a high Fermi velocity comparable to that of graphene, and the QSHphase remains robust on a NaCl substrate. These remarkable properties place TB-Bi among the most promising 2D TIs for high-speed spintronic devices, and the present results provide insights into the intriguing QSH phenomenon in this new Bi structure and offer guidance for its implementation in potential applications.

Non-Fermi liquid theory of quantum hall effects

Within the Grassmannian U(2N)/U(N) x U(N) nonlinear sigma-model representation of localization, one can study the low-energy dynamics of both a free and interacting electron gas. We study the crossover between these two fundamentally different physical problems. We show how the topological arguments for the exact quantization of the Hall conductance are extended to include the Coulomb interaction problem. We discuss dynamical scaling and make contact with the theory of variable range hopping. (C) 2005 Pleiades Publishing, Inc.

Hall thruster sequencer using Intel-8051 microcontroller for ion thrust measurement

Hall thrusters, such as Stationary Plasma Thruster (SPT), have been widely used on board modern satellites placed in geo-synchronows orbits for reasons such as orbit maintenance, repositioning and attitude control. In order to study the performance of the stationary plasma thruster, the thrust produced by it has been measured, using a thrust balance with strain gauge sensors under vacuum conditions, by activating the thruster. This activation of thruster has been carried out by switching ON and switching OFF of the necessary power supplies and control of other feed system such as the propellant flow in a particular sequence. Hitherto, these operations were done manually in the required sequence. This paper reports the attempt made to automate the sequential operation of the power supplies and the necessary control valves of the feed system using Intel 8051 microcontroller. This automation has made thrust measurements easier and more sophisticated.

AC transport at holographic quantum hall transitions

We compute AC electrical transport at quantum Hall critical points, as modeled by intersecting branes and gauge/gravity duality. We compare our results with a previous field theory computation by Sachdev, and find unexpectedly good agreement. We also give general results for DC Hall and longitudinal conductivities valid for a wide class of quantum Hall transitions, as well as (semi)analytical results for AC quantities in special limits. Our results exhibit a surprising degree of universality; for example, we find that the high frequency behavior, including subleading behavior, is identical for our entire class of theories.

Fractional quantum Hall edge: Effect of nonlinear dispersion and edge roton

According to Wen's theory, a universal behavior of the fractional quantum Hall edge is expected at sufficiently low energies, where the dispersion of the elementary edge excitation is linear. A microscopic calculation shows that the actual dispersion is indeed linear at low energies, but deviates from linearity beyond certain energy, and also exhibits an "edge roton minimum." We determine the edge exponent from a microscopic approach, and find that the nonlinearity of the dispersion makes a surprisingly small correction to the edge exponent even at energies higher than the roton energy. We explain this insensitivity as arising from the fact that the energy at maximum spectral weight continues to show an almost linear behavior up to fairly high energies. We also study, in an effective-field theory, how interactions modify the exponent for a reconstructed edge with multiple edge modes. Relevance to experiment is discussed.