Ferromagnetism of Weakly-Interacting Electrons in Disordered Systems

It was realized two decades ago that the two-dimensional diffusive Fermi liquid phase is unstable against arbitrarily weak electron-electron interactions. Recently, using the nonlinear sigma model developed by Finkelstein, several authors have shown that the instability leads to a ferromagnetic state. In this paper, we consider diffusing electrons interacting through a ferromagnetic exchange interaction. Using the Hartree-Fock approximation to directly calculate the electron self energy, we find that the total energy is minimized by a finite ferromagnetic moment for arbitrarily weak interactions in two dimensions and for interaction strengths exceeding a critical proportional to the conductivity in three dimensions. We discuss the relation between our results and previous ones

A study to evaluate the clinical outcome of drug-eluting vs. bare-metal stents for acute coronary syndrome patients during commercial use in real setting

Background: This study compared clinical outcome of Drug Eluting Stents (DES) versus Bare Metal Stents (BMS) in coronary arteries in patients with Acute Coronary Syndromes.Methods: A retrospective, observational study was carried out in an inpatient setting of the private tertiary care hospital. Patients with >18 years, diagnosed for Acute Coronary Syndromes (ACS), required intervention in coronary artery with implantation of Drug Eluting Stents (DES) or Bare Metal Stents (BMS) were recruited in the study. The data had been collected from file or database of the hospital. All subjects were followed for major adverse cardiac event.Results: A total of 202 patients who underwent percutaneous coronary intervention (PCI) were enrolled into DES group (n=101) and BMS group (n=101). All patients were followed up at 1 month, 3 months, 6 months & 12 months for Major Adverse Cardiac Events (MACE). Clinical outcomes during 12 months were compared between DES group & BMS group. Overall MACE rates were reported non-significantly high in BMS group patients (14.85%) compare to DES group patients (8.91%) (p=0.458). However, DES group had lower rates of death (0.99% vs 1.98%, p=0.57), rate of MI (3.96% vs 4.95% p=0.73), rate of revascularization (1.98% vs 3.96% p=0.42) & rate of sub acute thrombosis (1.98% vs 3.96% p=0.42) and higher rate of bleeding (1.98% vs 0.99% p=0.57) compare to cohort-II.Conclusions: The use of DES in the setting of Acute Coronary Syndrome is associated with lower Major Adverse Cardiac Event (MACE) rate compared to BMS without compromising the overall safety over the course of one-year follow-up. The long-term safety of drug-eluting stents needs to be ascertained in large, randomized trials

A Study to Compare Major Adverse Cardiac Event in Patient Undergoing PCI with Drug Eluting Stents Vs Bare Metal Stents

This study compared Major Adverse Cardiac Event in patient with Acute Coronary Syndromes undergoing PCI with Drug Eluting Stents Vs Bare Metal Stents. A retrospective, observational study was carried out in an inpatient setting of the private tertiary care hospital. Patients with >18 years, diagnosed for Acute Coronary Syndromes (ACS), required intervention in coronary artery with implantation of Drug Eluting Stents (DES) or Bare Metal Stents (BMS) were recruited in the study. The data had been collected from file or database of the hospital. All subjects were followed for major adverse cardiac event. Result. A total of 202 patients who underwent percutaneous coronary intervention (PCI) were enrolled into DES group (N=101) and BMS group (N=101).  All patients were followed up at 1 month, 3 months, 6 months & 12 months for Major Adverse Cardiac Events (MACE). Clinical outcomes during 12 months were compared between DES group & BMS group. There was no significant difference in baseline parameters including demographic, risk factors of ACS, diagnosis, angiographic parameters between both groups. Overall MACE rates were reported non-significantly high in BMS group patients (14.85%) compare to DES group patients (8.91%) (P=0.458). However, DES group had lower rates of death (0.99% vs 1.98%, P=0.57), rate of MI (3.96% vs 4.95% P=0.73), rate of revascularization (1.98% vs 3.96% p=0.42) & rate of sub acute thrombosis (1.98% vs 3.96% P=0.42) and higher rate of bleeding (1.98% vs 0.99% p=0.57) compare to cohort-II. Conclusion. The use of DES in the setting of Acute Coronary Syndrome is associated with lower Major Adverse Cardiac Event (MACE) rate compared to BMS without compromising the overall safety over the course of one-year follow-up. The long-term safety of drug-eluting stents needs to be ascertained in large, randomized trials.DOI: http://dx.doi.org/10.11591/ijphs.v1i2.125

Coulomb Blockade Doppelgangers in Quantum Hall States

In this paper, we ask the question: How well can Coulomb blockade experiments correctly identify and distinguish between different topological orders in quantum Hall states? We definitively find the answer to be: Quite poorly. In particular, we write the general expression for the spacing of resonance peaks in a simple form that explicitly displays its dependence on the conformal scaling dimensions of the systems' edge modes. This form makes transparent the general argument that the Coulomb blockade peak spacings do not provide a strongly indicative signature of the topological order of the system, since it is only weakly related to the braiding statistics. We bolster this general argument with examples for all the most physically relevant non-Abelian candidate states, demonstrating that they have Coulomb blockade doppelgangers -- candidate states at the same filling fraction with identical Coulomb blockade signatures, but dramatically different topological orders and braiding statistics.Comment: 12 pages, 1 figure; portions of this paper were formerly included in Appendix C of arXiv:0903.3108; v2: examples added, minor corrections made; v3: discussions of non-uniform filling and of hierarchical counterparts of multi-component states added, minor corrections mad

An extended Hubbard model with ring exchange: a route to a non-Abelian topological phase

We propose an extended Hubbard model on a 2D Kagome lattice with an additional ring-exchange term. The particles can be either bosons or spinless fermions . At a special filling fraction of 1/6 the model is analyzed in the lowest non-vanishing order of perturbation theory. Such ``undoped'' model is closely related to the Quantum Dimer Model. We show how to arrive at an exactly soluble point whose ground state manifold is the extensively degenerate ``d-isotopy space'', a necessary precondition for for a certain type of non-Abelian topological order. Near the ``special'' values, $d = 2 \cos \pi/(k+2)$, this space is expected to collapse to a stable topological phase with anyonic excitations closely related to SU(2) Chern-Simons theory at level k.Comment: 4 pages, 2 colour figures, submitted to PRL. For an extended treatment of a more general family of models see cond-mat/030912