Circuit QED and sudden phase switching in a superconducting qubit array

Superconducting qubits connected in an array can form quantum many-body systems such as the quantum Ising model. By coupling the qubits to a superconducting resonator, the combined system forms a circuit QED system. Here, we study the nonlinear behavior in the many-body state of the qubit array using a semiclassical approach. We show that sudden switchings as well as a bistable regime between the ferromagnetic phase and the paramagnetic phase can be observed in the qubit array. A superconducting circuit to implement this system is presented with realistic parameters .Comment: 4 pages, 3 figures, submitted for publication

Field Dependent Phase Diagram of the Quantum Spin Chain (CH3)2NH2CuCl3

Although (CH3)2NH2CuCl3 (MCCL) was first examined in the 1930's [1], there are open questions regarding the magnetic dimensionality and nature of the magnetic properties. MCCL is proposed to be a S=1/2 alternating ferromagnetic antiferromagnetic spin chain alternating along the crystalline a-axis [2,3]. Proposed ferromagnetic (JFM =1.3 meV) and antiferromagnetic (JAFM =1.1 meV) exchange constants make this system particularly interesting for experimental study. Because JFM and JAFM are nearly identical, the system should show competing behavior between S=1/2 (AFM) and S=1(FM) effects. We report low temperature magnetic field dependent susceptibility, chi(H), and specific heat, Cp, of MCCL. These provide an initial magnetic-field versus temperature phase diagram. A zero-field phase transition consistent with long range magnetic order is observed at T=0.9 K. The transition temperature can be reduced via application of a magnetic field. We also present comparisons to a FM/AFM dimer model that accounts for chi(T,H=0) and Cp(H,T).Comment: 2 pages, 1 figure included in text. Submitted to proceedings of 24th International Conference on Low Temperature Physics, August 200

Pathological Gambling : A Comprehensive Review

Due to recent changes of gambling laws, accessibility to gambling has become more widespread and thus, there has also been an increase in the prevalence of pathological gambling (PG). The wide range of social, economic, and psychological problems associated with PG are well known. There is a need for better understanding of PG and this review attempts to do so. Literature searches using the Medline and PsycINFO databases were used. Critical examining of the literature showed that familial/genetic, sociological, and individual factors (e.g., an individual's personality, biochemistry, psychological states, and cognitions) are implicated in the development and maintenance of PG, yet at present, the evidences are not solid. Similarly, there have been a lot of theories for PG but again, none of them are solid enough to provide a clear understanding of PG. Recent psychological-based theories seem to provide some solid ground for further research. We highlight four areas for future consideration for research. (1) Most studies have generalized findings from one form of gambling to another. It is suggested that it is now not tenable to consider gambling as a single phenomenon that can explain all forms of gambling. (2) Almost all of the studies in the gambling literature are Western-based and the results are often generalized to other ethnic and cultural groups. There is now an urgent need to close this gap. (3) Future studies need to address methodological problems in the current gambling/PG literature. (4) Almost all of the gambling literature has focused on the issue of why people start gambling. It is suggested that looking at variables as to why people stop gambling in a single episode may be a more fruitful area of research then why people start gambling. This is because what motivates one to continue gambling, despite losses in a session and across sessions, is a characteristic that distinguishes nonproblem gamblers from problem gamblers and pathological gamblers (PGs)

Changes to automatic thoughts and dysfunctional attitudes in group CBT for depression

The present study sought to clarify the role of cognitive change in Cognitive Behavioural Therapy (CBT) by examining the relationship between depression outcome and changes to automatic thoughts and dysfunctional attitudes at different points of therapy. Thirty patients suffering from Major Depression (MDD) or Dysthymia attended the 12 sessions of a group CBT program. Multiple regressions found total scores on the Automatic Thoughts Questionnaire (ATQ) and cumulative change scores on the Dysfunctional Attitudes Scale (DAS) to predict scores on the Beck Depression Inventory (BDI) at later stages of therapy, though neither form of cognition was predictive from earlier stages of therapy. Only scores on the ATQ were significantly related to both cognitive and somatic subscales of the BDI, indicating that automatic thoughts are more directly related to cognitive change than dysfunctional attitudes. Overall findings suggest that significant reductions in both automatic thoughts and dysfunctional attitudes are related to non-clinical levels of depressive symptoms at the end of the treatment

A review on assessment and treatment for depression in Malaysia.

This paper aimed to review the literature on depression that focused on its assessment and treatment in Malaysia. PsycINFO, Medline, local journals were searched, and 18 published articles were included in this paper. Results indicate that research on depression in Malaysia, particularly validation studies and psychotherapy research, was weak and fragmented, with minimal empirical evidence available. Pharmacotherapy still dominated the treatment for depression, and, in terms of psychotherapy, Cognitive Behavioural Therapy (CBT) was recently practiced, but only a few studies have reported on the treatment efficacy of CBT. Major limitations of studies were noted, and, consequently, the problems that are associated with the implementation and future direction of clinical and research on depression in Malaysia were discussed. In short, the contribution of empirical research on the assessment and treatment for depression remained inconsistent and fragmented and urgently in need of further empirical investigation

The K\"ahler-Ricci flow with positive bisectional curvature

We show that the K\"ahler-Ricci flow on a manifold with positive first Chern class converges to a K\"ahler-Einstein metric assuming positive bisectional curvature and certain stability conditions.Comment: 15 page

Superconducting correlations in ultra-small metallic grains

To describe the crossover from the bulk BCS superconductivity to a fluctuation-dominated regime in ultrasmall metallic grains, new order parameters and correlation functions, such as ``parity gap'' and ``pair-mixing correlation function'', have been recently introduced. In this paper, we discuss the small-grain behaviour of the Penrose-Onsager-Yang off-diagonal long-range order (ODLRO) parameter in a pseudo-spin representation. Relations between the ODLRO parameter and those mentioned above are established through analytical and numerical calculations.Comment: 7 pages, 1 figur