The system of two coupled Bose-Einstein condensates is mapped onto a uniaxial spin with an applied magnetic field. The mean-field interaction, the coupling and the asymmetry or the detuning correspond to the anisotropy, the transverse field, and the longitudinal field, respectively. A generalized Bloch equation is derived. In the low barrier limit for the quasi-spin model, the tunneling rate is...

Polaron pairs are intermediate electronic states that are integral to the optoelectronic conversion process in organic semiconductors. Here, we report on electrically detected spin echoes arising from direct quantum control of polaron pair spins in an organic light-emitting diode at room temperature. This approach reveals phase coherence on a microsecond time scale, and offers a direct way to p...

We study M-theory on two classes of manifolds of Spin(7) holonomy that are developing an isolated conical singularity. We construct explicitly a new class of Spin(7) manifolds and analyse in detail the topology of the corresponding classical spacetimes. We discover also an intricate interplay between various anomalies in M-theory, string theory, and gauge theory within these models, and in part...

II. Classical and Path Integral Monte Carlo (Filinov, Bonitz; Nov. 10,12,14, 17) a) Introduction to classical Metropolis Monte Carlo b) Quantum Statistics, Density matrix c) Feynman’s path integral. Mapping onto an effective classical system d) Spin statistics, exchange, Fermion sign problem e) Generalized Metropolis algorithm for quantum systems, PIMC f) High-temperature N-particle density mat...

Recently, a functional integral representation was proposed by Weller [1], in which the fermionic fields strictly satisfy the constraint of no double occupancy at each lattice site. This is achieved by introducing spin dependent Bose fields. The functional integral method is applied to the single impurity Anderson model both in the Kondo and mixed-valence regime. The f-electron Green's function...

We propose a system of nonlinear integral equations (NLIE) which describes the thermodynamics of the Uq( ̂ sl(r + 1)) Perk-Schultz model. These NLIE correspond to a trigonometric analogue of our previous result, and contain only r unknown functions. In particular, they reduce to Takahashi’s NLIE for the XXZ spin chain if r = 1. We also calculate the high temperature expansion of the free energy....

Intracellular accumulation of lipids and swollen dysfunctional lysosomes are linked to several neurodegenerative diseases, including lysosomal storage disorders (LSD). Detailed characterization of lipid metabolic changes in relation to the onset and progression of neurodegeneration is currently missing. We systematically analyzed lipid perturbations in spinster (spin) mutants, a Drosophila mode...

We have performed measurements of the magnetic susceptibility of NaV2O5 between 2 and 400 K. The high temperature part is typical of spin 1/2 chains with a nearest–neighbour antiferromagnetic exchange integral of 530 K. We develop a model for the susceptibility of a system with finite chains to account for the low temperature part of the data, which cannot be fitted by a standard Curie-Weiss te...

We propose a nonlinear integral equation (NLIE) with only one unknown function, which gives the free energy of the integrable one dimensional Heisenberg model with arbitrary spin. In deriving the NLIE, the quantum Jacobi-Trudi and Giambelli formula (BazhanovReshetikhin formula), which gives the solution of the T -system, plays an important role. In addition, we also calculate the high temperatu...

We have performed measurements of the magnetic susceptibility of NaV2O5 between 2 and 400 K. The high temperature part is typical of spin 1/2 chains with a nearest–neighbour antiferromagnetic exchange integral J of 529 K. We develop a model for the susceptibility of a system with finite chains to account for the low temperature part of the data, which cannot be fitted by a standard Curie-Weiss ...