Na 1 Nachlass Max Horkheimer, 36 - Korrespondenzen u.a. mit Karl Menninger vom The Menninger Clinic, The Menninger Sanatorium, Topeka, Kansas (p. I 18, 188-334)

15 Brief zwischen Heinrich Meng und Max Horkheimer sowie Briefwechsel mit The Johns Hopkins Hospital, Baltimore Maryland, 1935-1940; 4 Briefe zwischen dem The Johns Hopkins Hospital, Baltimore, Maryland und Max Horkheimer, 1940; 1 Brief von Werner Münsterberger an Max Horkheimer, 13.03.1940; 44 Briefe zwischen Karl Menninger vom The Menninger Clinic, The Menninger Sanatorium, Topeka, Kansas und Max Horkheimer, 1938-1941;

Na 1 Nachlass Max Horkheimer, 455 - Korrespondenzen u.a. mit Margo H. Wolff und Karl August Wittfogel (p. V 173, 210-429)

19 Briefe zwischen Lisa Witherell (geb. Richter) und Max Horkheimer, 1963-1971; 2 Briefe zwischen Werner Wittayer (stud. phil.) und Max Horkheimer, 1964; 4 Drucksachen vom Landtagspräsidenten Otto Witte an Max Horkheimer, 1952-1954; 2 Briefe an Otto Witte von Max Horkheimer, 1952-1953; 1 Todesanzeige, 1963; 4 Briefe zwischen der Studentin Ulrike Wittenberg und Max Horkheimer, 1972-1973; 4 Briefe zwischen dem Professor Karl A. Wittfogel und Max Horkheimer, 1972; 3 Briefe zwischen dem Oberstudiendirektor Dr. Kurt Debus und Max Horkheimer, 1967; 3 Briefe zwischen David Wodlinger und Max Horkheimer, 1960; 2 Briefe zwischen Dr. Herman Wohlstein und Max Horkheimer, 1965; 16 Briefe an Johanna Woitschach von Max Horkheimer, 1970-1973 (die Briefe an Max Horkheimer wurden zurückverlangt); 1 Brief von Ernst Wolf an Max Horkheimer, San Francisco, 1954; 3 Briefe zwischen dem Diplom-Psychologen Heinz E. Wolf und Max Horkheimer, 1958; 13 Briefe zwischen dem Oberstudiendirektor Oskar Wolfenstädter und Max Horkheimer, 1968-1969; 4 Briefe zwischen der Ordensschwester Katherine Wolff und Max Horkheimer, 1970-1971; 25 Briefe zwischen Margo H. Wolff und Max Horkheimer, 1962-1973; 11 Briefe zwischen dem Professor Max Wolff und Max Horkheimer, 1960; 3 Briefe zwischen dem Professor Manfred Wolfson und Max Horkheimer, 1971; 6 Briefe von der Physiotherapeutin Helga Wolk an Max Horkheimer, 1970-1971; 13 Briefe zwischen Hedwig G. de Wollenberger und Max Horkheimer, 1966-1970; 1 Brief an den Professor Günther Wollheim von Max Horkheimer, 1965; 4 Briefe zwischen Johanna Wopperer-Ege und Max Horkheimer, 1970; 5 Briefe zwischen Anton Wopperer und Max Horkheimer, 1969-1970; 3 Briefe an die World Future Society von Max Horkheimer, 1969-1973; 2 Briefe zwischen dem World Jewish Congress und Max Horkheimer, 1970; 2 Briefe zwischen dem Professor Theodor Würtenberger und Max Horkheimer, 1964; 3 Briefe zwischen der Würtembergischen Landesbibliothek und Max Horkheimer, 1969; 16 Briefe zwischen Rösle Wüstholz und Max Horkheimer, 1951-1959; 2 Briefe zwischen Christoph Wulf und Max Horkheimer, 1973; 1 Brief an Jssy Wygoda von Max Horkheimer, 1964; 2 Briefe zwischen Dr. Hans von Wyl und Max Horkheimer, 1971; 2 Briefe zwischen Jacques Wyler und Max Horkheimer, 1973; 1 Brief von Gisela Wysocki an Max Horkheimer, o.J. (1973?);

Gründung und verwaltung der reichsmarken unter Karl dem Grossen und Otto dem Grossen. I. t.: Das markensystem Karls des Grossen.

"Wissenschaftliche beigabe zum Jahresberichte des gymnasiums und der realschule zu Bremerhaven."

Unusual magneto-optical phenomenon reveals low energy spin dispersion in the spin-1 anisotropic Heisenberg antiferromagnetic chain system NiCl(2)-4SC(NH(2))(2)

Electron paramagnetic resonance measurements of NiCl(2)-4SC(NH(2))(2) reveal the low-energy spin dispersion, including a magnetic-field interval in which the two-magnon continuum is within k(B)T of the ground state, allowing a continuum of excitations over a range of k states, rather than only the k=0 single-magnon excitations. This produces a novel Y shape in the frequency-field EPR spectrum measured at T >= 1.5 K. Since the interchain coupling J(perpendicular to)< k(B)T, this shape can be reproduced by a single S=1 antiferromagnetic Heisenberg chain with a strong easy-plane single-ion anisotropy. Importantly, the combination of experiment and modeling we report herein demonstrates a powerful approach to probing spin dispersion in a wide range of interacting magnetic systems without the stringent sample requirements and complications associated with inelastic scattering experiments.

Renyi entropy and parity oscillations of anisotropic spin-s Heisenberg chains in a magnetic field

Using the density matrix renormalization group, we investigate the Renyi entropy of the anisotropic spin-s Heisenberg chains in a z-magnetic field. We considered the half-odd-integer spin-s chains, with s = 1/2, 3/2, and 5/2, and periodic and open boundary conditions. In the case of the spin-1/2 chain we were able to obtain accurate estimates of the new parity exponents p(alpha)((p)) and p(alpha)((o)) that gives the power-law decay of the oscillations of the alpha-Renyi entropy for periodic and open boundary conditions, respectively. We confirm the relations of these exponents with the Luttinger parameter K, as proposed by Calabrese et al. [Phys. Rev. Lett. 104, 095701 (2010)]. Moreover, the predicted periodicity of the oscillating term was also observed for some nonzero values of the magnetization m. We show that for s > 1/2 the amplitudes of the oscillations are quite small and get accurate estimates of p(alpha)((p)) and p(alpha)((o)) become a challenge. Although our estimates of the new universal exponents p(alpha)((p)) and p(alpha)((o)) for the spin-3/2 chain are not so accurate, they are consistent with the theoretical predictions.

Half-Filled Layered Organic Superconductors and the Resonating-Valence-Bond Theory of the Hubbard-Heisenberg Model

We present a resonating-valence-bond theory of superconductivity for the Hubbard-Heisenberg model on an anisotropic triangular lattice. Our calculations are consistent with the observed phase diagram of the half-filled layered organic superconductors, such as the beta, beta('), kappa, and lambda phases of (BEDT-TTF)(2)X [bis(ethylenedithio)tetrathiafulvalene] and (BETS)(2)X [bis(ethylenedithio)tetraselenafulvalene]. We find a first order transition from a Mott insulator to a d(x)(2)-y(2) superconductor with a small superfluid stiffness and a pseudogap with d(x)(2)-y(2) symmetry.

The Heisenberg antiferromagnet on an anisotropic triangular lattice: linear spin-wave theory

We consider the effect of quantum spin fluctuations on the ground-state properties of the Heisenberg antiferromagnet on an anisotropic triangular lattice using linear spin-wave (LSW) theory. This model should describe the magnetic properties of the insulating phase of the kappa-(BEDT-TTF)(2)X family of superconducting molecular crystals. The ground-state energy, the staggered magnetization, magnon excitation spectra, and spin-wave velocities are computed as functions of the ratio of the antiferromagnetic exchange between the second and first neighbours, J(2)/J(1). We find that near J(2)/J(1) = 0.5, i.e., in the region where the classical spin configuration changes from a Neel-ordered phase to a spiral phase, the staggered magnetization vanishes, suggesting the possibility of a quantum disordered state. in this region, the quantum correction to the magnetization is large but finite. This is in contrast to the case for the frustrated Heisenberg model on a square lattice, for which the quantum correction diverges logarithmically at the transition from the Neel to the collinear phase. For large J(2)/J(1), the model becomes a set of chains with frustrated interchain coupling. For J(2) > 4J(1), the quantum correction to the magnetization, within LSW theory, becomes comparable to the classical magnetization, suggesting the possibility of a quantum disordered state. We show that, in this regime, the quantum fluctuations are much larger than for a set of weakly coupled chains with non-frustrated interchain coupling.

Phase diagram for a class of spin-1/2 Heisenberg models interpolating between the square-lattice, the triangular-lattice, and the linear-chain limits

We study the spin-1/2 Heisenberg models on an anisotropic two-dimensional lattice which interpolates between the square lattice at one end, a set of decoupled spin chains on the other end, and the triangular-lattice Heisenberg model in between. By series expansions around two different dimer ground states and around various commensurate and incommensurate magnetically ordered states, we establish the phase diagram for this model of a frustrated antiferromagnet. We find a particularly rich phase diagram due to the interplay of magnetic frustration, quantum fluctuations, and varying dimensionality. There is a large region of the usual two-sublattice Neel phase, a three-sublattice phase for the triangular-lattice model, a region of incommensurate magnetic order around the triangular-lattice model, and regions in parameter space where there is no magnetic order. We find that the incommensurate ordering wave vector is in general altered from its classical value by quantum fluctuations. The regime of weakly coupled chains is particularly interesting and appears to be nearly critical. [S0163-1829(99)10421-1].

Phase diagram of a Heisenberg spin-Peierls model with quantum phonons

Using a new version of the density-matrix renormalization group we determine the phase diagram of a model of an antiferromagnetic Heisenberg spin chain where the spins interact with quantum phonons. A quantum phase transition from a gapless spin-fluid state to a gapped dimerized phase occurs at a nonzero value of the spin-phonon coupling. The transition is in the same universality class as that of a frustrated spin chain, to which the model maps in the diabatic limit. We argue that realistic modeling of known spin-Peierls materials should include the effects of quantum phonons.

The Tausk controversy on the foundations of quantum mechanics: Physics, philosophy, and politics

In 1966 the Brazilian physicist Klaus Tausk (b. 1927) circulated a preprint from the International Centre for Theoretical Physics in Trieste, Italy, criticizing Adriana Daneri, Angelo Loinger, and Giovanni Maria Prosperi`s theory of 1962 on the measurement problem in quantum mechanics. A heated controversy ensued between two opposing camps within the orthodox interpretation of quantum theory, represented by Leon Rosenfeld and Eugene P. Wigner. The controversy went well beyond the strictly scientific issues, however, reflecting philosophical and political commitments within the context of the Cold War, the relationship between science in developed and Third World countries, the importance of social skills, and personal idiosyncrasies.

Large-N solutions of the Heisenberg and Hubbard-Heisenberg models on the anisotropic triangular lattice: application to Cs2CuCl4 and to the layered organic superconductors kappa-(BEDT-TTF)(2)X (BEDT-TTF bis(ethylene-dithio)tetrathiafulvalene); X anion)

We solve the Sp(N) Heisenberg and SU(N) Hubbard-Heisenberg models on the anisotropic triangular lattice in the large-N limit. These two models may describe respectively the magnetic and electronic properties of the family of layered organic materials K-(BEDT-TTF)(2)X, The Heisenberg model is also relevant to the frustrated antiferromagnet, Cs2CuCl4. We find rich phase diagrams for each model. The Sp(N) :antiferromagnet is shown to have five different phases as a function of the size of the spin and the degree of anisotropy of the triangular lattice. The effects of fluctuations at finite N are also discussed. For parameters relevant to Cs2CuCl4 the ground state either exhibits incommensurate spin order, or is in a quantum disordered phase with deconfined spin-1/2 excitations and topological order. The SU(N) Hubbard-Heisenberg model exhibits an insulating dimer phase, an insulating box phase, a semi-metallic staggered flux phase (SFP), and a metallic uniform phase. The uniform and SFP phases exhibit a pseudogap, A metal-insulator transition occurs at intermediate values of the interaction strength.

Quantum theory of the far-off-resonance continuous-wave Raman laser: Heisenberg-Langevin approach

We present the quantum theory of the far-off-resonance continuous-wave Raman laser using the Heisenberg-Langevin approach. We show that the simplified quantum Langevin equations for this system are mathematically identical to those of the nondegenerate optical parametric oscillator in the time domain with the following associations: pump pump, Stokes signal, and Raman coherence idler. We derive analytical results for both the steady-state behavior and the time-dependent noise spectra, using standard linearization procedures. In the semiclassical limit, these results match with previous purely semiclassical treatments, which yield excellent agreement with experimental observations. The analytical time-dependent results predict perfect photon statistics conversion from the pump to the Stokes and nonclassical behavior under certain operational conditions.

Mathematical aspects of the Heisenberg uncertainty principle within local fractional Fourier analysis

In this paper, we discuss the mathematical aspects of the Heisenberg uncertainty principle within local fractional Fourier analysis. The Schrödinger equation and Heisenberg uncertainty principles are structured within local fractional operators.