Zero-Bias States and the Mechanism of the Surface d->d+is Transition

We study the physical mechanism of the surface d->d+is transition proposed as the interpretation of results of tunneling experiments into ab planes. We base our argument on first-order perturbation theory and show that the zero-bias states drive the transition. We support the argument by various estimates and consistency checks.Comment: 30 pages, 8 figure

Becoming music teachers: preservice music teachers' early beliefs about music teaching and learning

A major component in the socialisation of teachers is the development of a belief system, which is closely related to their identities. A better understanding of the belief systems and identities of preservice teachers when they begin the process of secondary socialisation could influence approaches to teacher preparation. The purpose of this study was to understand preservice teachers’ initial beliefs about music education as well as their conceptualisations of their identities. Data were drawn from selected assignments completed by students who were enrolled in an introductory-level music education course at a university in the northeastern United States. Through an analysis of the data using a constant comparative approach, three broad themes emerged: A desire to share and develop passion; expressing, feeling, and emotional growth; and providing opportunities for all students. Implications for teacher educators and suggestions for further research are discussed.Accepted manuscrip

Domestic open market operations during 2002

Open market operations ; Monetary policy ; Federal Open Market Committee

Time-dependent Correlation Functions in Open Quadratic Fermionic Systems

We formulate and discuss explicit computation of dynamic correlation functions in open quadradic fermionic systems which are driven and dissipated by the Lindblad jump processes that are linear in canonical fermionic operators. Dynamic correlators are interpreted in terms of local quantum quench where the pre-quench state is the non-equilibrium steady state, i.e. a fixed point of the Liouvillian. As an example we study the XY spin 1/2 chain and the Kitaev Majorana chains with boundary Lindblad driving, whose dynamics exhibits asymmetric (skewed) light cone behaviour. We also numerically treat the two dimensional XY model and the XY spin chain with additional Dzyaloshinskii-Moriya interactions. The latter exhibits a new non-equilibrium phase transition which can be understood in terms of bifurcations of the quasi-particle dispersion relation. Finally, considering in some detail the periodic Kitaev chain (fermionic ring) with dissipation at a single (arbitrary) site, we present analytical expressions for the first order corrections (in the strength of dissipation) to the spectrum and the non-equilibrium steady state (NESS) correlation functions.Comment: 25 pages, 10 figure

Many-body quantum chaos: Analytic connection to random matrix theory

A key goal of quantum chaos is to establish a relationship between widely observed universal spectral fluctuations of clean quantum systems and random matrix theory (RMT). For single particle systems with fully chaotic classical counterparts, the problem has been partly solved by Berry (1985) within the so-called diagonal approximation of semiclassical periodic-orbit sums. Derivation of the full RMT spectral form factor $K(t)$ from semiclassics has been completed only much later in a tour de force by Mueller et al (2004). In recent years, the questions of long-time dynamics at high energies, for which the full many-body energy spectrum becomes relevant, are coming at the forefront even for simple many-body quantum systems, such as locally interacting spin chains. Such systems display two universal types of behaviour which are termed as `many-body localized phase' and `ergodic phase'. In the ergodic phase, the spectral fluctuations are excellently described by RMT, even for very simple interactions and in the absence of any external source of disorder. Here we provide the first theoretical explanation for these observations. We compute $K(t)$ explicitly in the leading two orders in $t$ and show its agreement with RMT for non-integrable, time-reversal invariant many-body systems without classical counterparts, a generic example of which are Ising spin 1/2 models in a periodically kicking transverse field.Comment: 10 pages in RevTex with 4 figures and a few diagrams; v3: version accepted by PR

Domestic open market operations during 2001

Open market operations ; Monetary policy ; Federal Open Market Committee

Policy and the K–12 music teacher: a literature review

Music teaching lies at the intersection of policy, research, and practice. An awareness of policy context and how policies affect teachers is essential for those in the music education profession. In particular, such an understanding can allow teachers to better adapt to and implement policies so that they might maintain and grow their programs and feel more satisfied in their jobs. This review of literature investigates scholarly literature published in music education research journals with implications for teachers’ classroom practice and their professional lives. It includes studies of resources, organizations, and educational reform, teachers and teaching, institutions and actors, and access, in addition to descriptions of policy. Implications for teachers related to policy awareness, access for all students to a variety of musical activities, and music education advocacy are discussed.Accepted manuscrip