Kinetic theory and thermalization of weakly interacting fermions

Weakly interacting quantum fluids allow for a natural kinetic theory description which takes into account the fermionic or bosonic nature of the interacting particles. In the simplest cases, one arrives at the Boltzmann-Nordheim equations for the reduced density matrix of the fluid. We discuss here two related topics: the kinetic theory of the fermionic Hubbard model, in which conservation of total spin results in an additional Vlasov type term in the Boltzmann equation, and the relation between kinetic theory and thermalization.Comment: 19 pages, submitted to proceedings of the conference "Macroscopic Limits of Quantum Systems", Munich, Germany, March 20-April 1, 2017 (eds. D. Cadamuro, M. Duell, W. Dybalski, S. Simonella

Fourier's Law for a Harmonic Crystal with Self-consistent Stochastic Reservoirs

We consider a d-dimensional harmonic crystal in contact with a stochastic Langevin type heat bath at each site. The temperatures of the "exterior" left and right heat baths are at specified values T_L and T_R, respectively, while the temperatures of the "interior" baths are chosen self-consistently so that there is no average flux of energy between them and the system in the steady state. We prove that this requirement uniquely fixes the temperatures and the self consistent system has a unique steady state. For the infinite system this state is one of local thermal equilibrium. The corresponding heat current satisfies Fourier's law with a finite positive thermal conductivity which can also be computed using the Green-Kubo formula. For the harmonic chain (d=1) the conductivity agrees with the expression obtained by Bolsterli, Rich and Visscher in 1970 who first studied this model. In the other limit, d>>1, the stationary infinite volume heat conductivity behaves as 1/(l_d*d) where l_d is the coupling to the intermediate reservoirs. We also analyze the effect of having a non-uniform distribution of the heat bath couplings. These results are proven rigorously by controlling the behavior of the correlations in the thermodynamic limit.Comment: 33 page

Loading of bosons in optical lattices into the p band

We present a method for transferring bosonic atoms residing on the lowest s-band of an optical lattice to the first excited p-bands. Our idea hinges on resonant tunneling between adjacent sites of accelerated lattices. The acceleration effectively shifts the quasi-bound energies on each site such that the system can be cast into a Wannier-Stark ladder problem. By adjusting the acceleration constant, a situation of resonant tunneling between the s- and p-bands is achievable. Within a mean-field model, considering 87Rb atoms, we demonstrate population transfer from the s- to the p-bands with around 95 % efficiency. Nonlinear effects deriving from atom-atom interactions, as well as coupling of the quasi bound Wannier-Stark states to the continuum, are considered.Comment: 8 pages, 7 figure

Translation of Goswami Harirai's Jarasandhavadha Mahakavyam from Sanskrit to English with a Critical Introduction

Not availabl

Analisis Faktor Kepuasan Komunikasi Organisasi Di Apartemen Metropolis Surabaya

Penelitian ini bertujuan untuk mengetahui faktor analisis yang memiliki kontribusi terbesar dalam kepuasan komunikasi organisasi di Metropolis Apartemen Surabaya. Kepuasan komunikasi Organisasi pada Apartemen Metropolis diukur oleh delapan faktor yaitu: iklim komunikasi, komunikasi atasan, Integrasi Organisasi, Kualitas media, komunikasi horizontal informal, komunikasi bawahan, dan umpan Balik, informasi mengenai organisasi secara keseluruhan.Metode yang digunakan dalam penelitian ini adalah analisis faktor dan juga metode deskriptif. Hasil dari penelitian ini menunjukkan bahwa faktor yang memiliki kontribusi terbesar dalam kepuasan komunikasi di Apartemen Metropolis adalah faktor komunikasi dengan atasan

Evidence of Cooper pair pumping with combined flux and voltage control

We have experimentally demonstrated pumping of Cooper pairs in a single-island mesoscopic structure. The island was connected to leads through SQUID (Superconducting Quantum Interference Device) loops. Synchronized flux and voltage signals were applied whereby the Josephson energies of the SQUIDs and the gate charge were tuned adiabatically. From the current-voltage characteristics one can see that the pumped current increases in 1e steps which is due to quasiparticle poisoning on the measurement time scale, but we argue that the transport of charge is due to Cooper pairs.Comment: 4 page

Impairments in motor coordination without major changes in cerebellar plasticity in the Tc1 mouse model of Down syndrome

Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of human chromosome 21 (Hsa21). Recently, O’Doherty et al. [An aneuploid mouse strain carrying human chromosome 21 with Down syndrome phenotypes. Science 309 (2005) 2033–2037] generated a trans-species aneuploid mouse line (Tc1) that carries an almost complete Hsa21. The Tc1 mouse is the most complete animal model for DS currently available. Tc1 mice show many features that relate to human DS, including alterations in memory, synaptic plasticity, cerebellar neuronal number, heart development and mandible size. Because motor deficits are one of the most frequently occurring features of DS, we have undertaken a detailed analysis of motor behaviour in cerebellum-dependent learning tasks that require high motor coordination and balance. In addition, basic electrophysiological properties of cerebellar circuitry and synaptic plasticity have been investigated. Our results reveal that, compared with controls, Tc1 mice exhibit a higher spontaneous locomotor activity, a reduced ability to habituate to their environments, a different gait and major deficits on several measures of motor coordination and balance in the rota rod and static rod tests. Moreover, cerebellar long-term depression is essentially normal in Tc1 mice, with only a slight difference in time course. Our observations provide further evidence that support the validity of the Tc1 mouse as a model for DS, which will help us to provide insights into the causal factors responsible for motor deficits observed in persons with DS

A Riemann-Hilbert problem with a vanishing coefficient and applications to Toeplitz operators

We study the homogeneous Riemann-Hilbert problem with a vanishing scalar-valued continuous coefficient. We characterize non-existence of nontrivial solutions in the case where the coefficient has its values along several rays starting from the origin. As a consequence, some results on injectivity and existence of eigenvalues of Toeplitz operators in Hardy spaces are obtained

Dynamical quantum phase transition of a two-component Bose-Einstein condensate in an optical lattice

We study dynamics of a two-component Bose-Einstein condensate where the two components are coupled via an optical lattice. In particular, we focus on the dynamics as one drives the system through a critical point of a first order phase transition characterized by a jump in the internal populations. Solving the time-dependent Gross-Pitaevskii equation, we analyze; breakdown of adiabaticity, impact of non-linear atom-atom scattering, and the role of a harmonic trapping potential. Our findings demonstrate that the phase transition is resilient to both contact interaction between atoms and external trapping confinement.Comment: 8 pages, 8 figure

Kinetic Limit for Wave Propagation in a Random Medium

We study crystal dynamics in the harmonic approximation. The atomic masses are weakly disordered, in the sense that their deviation from uniformity is of order epsilon^(1/2). The dispersion relation is assumed to be a Morse function and to suppress crossed recollisions. We then prove that in the limit epsilon to 0 the disorder averaged Wigner function on the kinetic scale, time and space of order epsilon^(-1), is governed by a linear Boltzmann equation.Comment: 71 pages, 3 figure