Fermionic topological quantum states as tensor networks

Tensor network states, and in particular projected entangled pair states, play an important role in the description of strongly correlated quantum lattice systems. They do not only serve as variational states in numerical simulation methods, but also provide a framework for classifying phases of quantum matter and capture notions of topological order in a stringent and rigorous language. The rapid development in this field for spin models and bosonic systems has not yet been mirrored by an analogous development for fermionic models. In this work, we introduce a tensor network formalism capable of capturing notions of topological order for quantum systems with fermionic components. At the heart of the formalism are axioms of fermionic matrix-product operator injectivity, stable under concatenation. Building upon that, we formulate a Grassmann number tensor network ansatz for the ground state of fermionic twisted quantum double models. A specific focus is put on the paradigmatic example of the fermionic toric code. This work shows that the program of describing topologically ordered systems using tensor networks carries over to fermionic models

Localization of bosonic atoms by fermionic impurities in a 3d optical lattice

We observe a localized phase of ultracold bosonic quantum gases in a 3-dimensional optical lattice induced by a small contribution of fermionic atoms acting as impurities in a Fermi-Bose quantum gas mixture. In particular we study the dependence of this transition on the fermionic 40K impurity concentration by a comparison to the corresponding superfluid to Mott insulator transition in a pure bosonic 87Rb gas and find a significant shift in the transition parameter. The observed shift is larger than expected based on a mean-field argument, which is a strong indication that disorder-related effects play a significant role.Comment: 4 pages, 4 figure

Intensity interferometry of single x-ray pulses from a synchrotron storage ring

We report on measurements of second-order intensity correlations at the high brilliance storage ring PETRA III using a prototype of the newly developed Adaptive Gain Integrating Pixel Detector (AGIPD). The detector recorded individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV and repetition rate of about 5 MHz. The second-order intensity correlation function was measured simultaneously at different spatial separations that allowed to determine the transverse coherence length at these x-ray energies. The measured values are in a good agreement with theoretical simulations based on the Gaussian Schell-model.Comment: 16 pages, 6 figures, 42 reference

Miscellanea in the Brāhmī Script from the Berezovsky and Krotkov Collections (IOM, RAS) with an appendix: ВФ-4190

Descriptive and Comparative Linguistic

Ab initio and nuclear inelastic scattering studies of Fe3_3Si/GaAs heterostructures

The structure and dynamical properties of the Fe$_3$Si/GaAs(001) interface are investigated by density functional theory and nuclear inelastic scattering measurements. The stability of four different atomic configurations of the Fe$_3$Si/GaAs multilayers is analyzed by calculating the formation energies and phonon dispersion curves. The differences in charge density, magnetization, and electronic density of states between the configurations are examined. Our calculations unveil that magnetic moments of the Fe atoms tend to align in a plane parallel to the interface, along the [110] direction of the Fe$_3$Si crystallographic unit cell. In some configurations, the spin polarization of interface layers is larger than that of bulk Fe$_3$Si. The effect of the interface on element-specific and layer-resolved phonon density of states is discussed. The Fe-partial phonon density of states measured for the Fe$_3$Si layer thickness of three monolayers is compared with theoretical results obtained for each interface atomic configuration. The best agreement is found for one of the configurations with a mixed Fe-Si interface layer, which reproduces the anomalous enhancement of the phonon density of states below 10 meVComment: 14 pages, 9 figures, 4 table

Clinical and hemodynamic determinants of left ventricular dimensions

This study was designed to quantitate the influence of 20 clinical, hemodynamic, and volume determinants of left ventricular (LV) structure. Systemic hemodynamics, intravascular volume, and LV echocardiographic measurements were collected in a heterogeneous population of 171 patients. Stepwise multiple-regression analysis indicated that body weight and body-surface area were the most powerful determinants of LV chamber size, wall thickness, and muscle mass. Age, a pressure independent determinant of myocardial mass, had no influence on chamber size or LV function. Arterial pressure correlated best with the relative wall thickness and chamber volume. Intravascular volume was a major discriminator for chamber volume, LV mass, and velocity of circumferential fiber shortening. It is concluded that body weight, arterial pressure, intravascular volume, and age are each independent determinants of the LV dimension. Systolic pressure most closely correlated with relative wall thickness and thereby is the best predictor of degree of concentric LV hypertrophy

Reflections in Systemic Family Psychotherapy and Adult Mental Health Services in the South East of Ireland; and beyond.

Systemic Family Psychotherapy (SFP) has been involved in the Carlow Kilkenny South Tipperary Adult Mental Services since 1994: in the main this involved meeting with service users, their families, couples and friends. However, from 2012 to 2019 five SFPs retired. This occurred when decisions were made by some Mental Health Management not to replace those SFPs that retired: thereby reducing the number of SFPs in the Southeast Adult Mental Health Services (AMHS); presumably due to funding difficulties at that time. However, as the months and years went by it became oblivious that two AMHSs were not going to employ SPTs. It was obvious that the AMHS in Waterford had never employed any SFT, and Wexford AMHS has only employed a half-time SFT for four Community Mental Teams. Consequently, this had an impact on the availability of SFPs in AMHSs in the south east AMHSs. However, on the other hand, the Carlow Kilkenny AMHS continues to be supported from Management and colleagues; SFTs since 1997. This is obvious as all Community Mental Health Teams refer service users attends the AMHSs in Carlow and Kilkenny, as well as their families/partners/friends for SFP. This article will try to ascertain how this came about, and what can be done to influences AMHS managers’ and concerning supporting SFPs. Key words: Family Therapy; Families; Mental Health Services; Family Meetings; Context in family therapy