Level correlations in integrable systems

We derive a simple analytical expression for the level correlation function of an integrable system. It accounts for both the lack of correlations at smaller energy scales and for global rigidity (level number conservation) at larger scales. We apply our results to a rectangle with incommensurate sides and show that they are in excellent agreement with the limiting cases established in the semiclassical theory of level rigidity.Comment: 5 page

Orbital Magnetism of 2D Chaotic Lattices

We study the orbital magnetism of 2D lattices with chaotic motion of electrons withing a primitive cell. Using the temperature diagrammatic technique we evaluate the averaged value and rms fluctuation of magnetic response in the diffusive regime withing the model of non-interacting electrons. The fluctuations of magnetic susceptibility turn out to be large and at low temperature can be of the order of $\chi_{L} (k_{F}l)^{3/2}$, where $k_{F}$ is the Fermi wavevector, $l$ is the mean free path, and $\chi_{L}$ is the Landau susceptibility. In the certain region of magnetic fields the paramagnetic contribution to the averaged response is field independent and larger than the absolute value of Landau response.Comment: 6 pages, Latex file, figures available upon reques

Level Correlations And Persistent Currents In Mesoscopic Metals

We use the exact correlation function of the density of energy levels in the magnetic field to evaluate persistent currents in mesoscopic metals. We also analyze the perturbation theory limit of the correlation function vis-a-vis the perturbation theory limit of the orbital response.Comment: 10 pages revte

Thermodynamics of Finite Quantum Systems: Application to Spin Magnetism II

We extend our study of thermodynamics of a Kubo particle to temperatures smaller than the interlevel spacing. We obtain the distribution functions of spin susceptibility and heat capacity for Poisson and Wigner-Dyson level statistics. We evaluate the line shape of the Knight shift due to spin effects both in a single particle and for the ensemble average and compare it with orbital and spin-orbit contributions.Comment: 20 pages (16 text, 4 figures) uu-encoded, z-compressed PostScript. Latest versions of manuscripts available at http://physuna.phs.uc.edu/professors/serota.html or by e-mail, by request from [email protected]

Orbital Magnetism and Current Distribution of Two-Dimensional Electrons under Confining Potential

The spatial distribution of electric current under magnetic field and the resultant orbital magnetism have been studied for two-dimensional electrons under a harmonic confining potential V(\vecvar{r})=m \omega_0^2 r^2/2 in various regimes of temperature and magnetic field, and the microscopic conditions for the validity of Landau diamagnetism are clarified. Under a weak magnetic field (\omega_c\lsim\omega_0, \omega_c being a cyclotron frequency) and at low temperature (T\lsim\hbar\omega_0), where the orbital magnetic moment fluctuates as a function of the field, the currents are irregularly distributed paramagnetically or diamagnetically inside the bulk region. As the temperature is raised under such a weak field, however, the currents in the bulk region are immediately reduced and finally there only remains the diamagnetic current flowing along the edge. At the same time, the usual Landau diamagnetism results for the total magnetic moment. The origin of this dramatic temperature dependence is seen to be in the multiple reflection of electron waves by the boundary confining potential, which becomes important once the coherence length of electrons gets longer than the system length. Under a stronger field (\omega_c\gsim\omega_0), on the other hand, the currents in the bulk region cause de Haas-van Alphen effect at low temperature as T\lsim\hbar\omega_c. As the temperature gets higher (T\gsim\hbar\omega_c) under such a strong field, the bulk currents are reduced and the Landau diamagnetism by the edge current is recovered.Comment: 15 pages, 11 figure

Harm reduction for the treatment of patients with severe injection-related infections: description of the Jackson SIRI Team

Introduction: Hospitalizations for severe injection-related infections (SIRI), such as endocarditis, osteomyelitis, and skin and soft tissue infections (SSTI) are increasingly common. People who inject drugs (PWID) experiencing SIRIs often receive inadequate substance use disorder (SUD) treatment and lack of access to harm reduction services. This translates into lengthy hospitalizations with high rates of patient-directed discharge, readmissions, and post-hospitalization mortality. The purpose of this study was to describe the development of an integrated “SIRI Team” and its initial barriers and facilitators to success. Materials and methods: The Jackson SIRI Team was developed to improve both hospital and patient-level outcomes for individuals hospitalized with SIRIs at Jackson Memorial Hospital, a 1550-bed public hospital in Miami, Florida, United States. The SIRI Team provides integrated infectious disease and SUD treatment across the healthcare system starting from the inpatient setting and continuing for 90-days post-hospital discharge. The team uses a harm reduction approach, provides care coordination, focuses on access to medications for opioid use disorder (MOUD), and utilizes a variety of infection and addiction treatment modalities to suit each individual patient. Results: Over the initial 8-months of the SIRI Team, 21 patients were treated with 20 surviving until discharge. Infections included osteomyelitis, endocarditis, bacteraemia/fungemia, SSTIs, and septic arthritis. All patients had OUD and 95% used stimulants. All patients were discharged on MOUD and 95% completed their prescribed antibiotic course. At 90-days post-discharge, 25% had been readmitted and 70% reported taking MOUD. Conclusions: A model of integrated infectious disease and SUD care for the treatment of SIRIs has the potential to improve infection and addiction outcomes. Providing attentive, patient-centered care, using a harm reduction approach can facilitate engagement of this marginalized population with the healthcare system.KEY MESSAGES Integrated infectious disease and addiction treatment is a novel approach to treating severe injection-related infections. Harm reduction should be applied to treating patients with severe injection-related infections with a goal of facilitating antibiotic completion, remission from substance use disorder, and reducing hospital readmissions

"Optical conductance fluctuations: diagrammatic analysis in Landauer approach and non-universal effects"

The optical conductance of a multiple scattering medium is the total transmitted light of a diffuse incoming beam. This quantity, very analogous to the electronic conductance, exhibits universal conductance fluctuations. We perform a detailed diagrammatic analysis of these fluctuations. With a Kadanoff-Baym technique all the leading diagrams are systematically generated. A cancellation of the short distance divergencies occurs, that yields a well behaved theory. The analytical form of the fluctuations is calculated and applied to optical systems. Absorption and internal reflections reduce the fluctuations significantly.Comment: 25 pages Revtex 3.0, 18 seperate postscript figure