Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization

We study numerically the universal conductance of Luttinger liquids wire with a single impurity via the Muti-scale Entanglement Renormalization Ansatz (MERA). The scale invariant MERA provides an efficient way to extract scaling operators and scaling dimensions for both the bulk and the boundary conformal field theories. By utilizing the key relationship between the conductance tensor and ground-state correlation function, the universal conductance can be evaluated within the framework of the boundary MERA. We construct the boundary MERA to compute the correlation functions and scaling dimensions for the Kane-Fisher fixed points by modeling the single impurity as a junction (weak link) of two interacting wires. We show that the universal behavior of the junction can be easily identified within the MERA and argue that the boundary MERA framework has tremendous potential to classify the fixed points in general multi-wire junctions.Comment: 14 pages, 18 figure

Determinants Of Customer-Perceived Service Quality In Senior-Care Industry And Their Relationship To Customer Satisfaction And Behavioral Intentions: Research Findings From Taiwan

The senior-care market has been on the rise in Taiwan, especially in rural areas. Soaring competition among senior-care operators has led to escalating consumer demands on performances, driving the industry to become more customer-oriented. The authors examined the relationship between service quality of senior care and customer satisfaction in rural Taiwan based on Parasuraman, Zeithmal and Berry’s SERVQUAL ten dimensions (i.e., access, communication, competence, courtesy, credibility, reliability, responsiveness, security, tangibles and understanding the customer) and Lee’s food service. Multiple regression was conducted to test the relationships. The statistical results showed that access, courtesy and food service are significantly and positively related to customer satisfaction. This finding, among others, suggests that senior-care operators in rural Taiwan might have overlooked the above mentioned three dimensions as factors leading to customer satisfaction and, ultimately, to a sustainable competitive edge

Construction of Spatial Mental Representation in Japanese Learners’ Listening: An Experimental Analysis using Manipulation of Verbal and Visuo-spatial Working Memory Capacities

We investigated the effects of verbal and visuo-spatial working memory (WM) capacities on spatial mental representation in second language listening by manipulating the length of the materials. In the experiment, an advanced class of Chinese learners learning Japanese were separated into four groups according to their verbal and visuo-spatial WM capacities. The learners were required to react to a judgement task in which they must judge whether the picture shown on the computer matches the sentences they had listened to previously. Two or four sentences were used in each trial. The correct rate and reaction time were used as dependent variables. As a result, only the main effect of the length of the materials was observed, which suggests that for Japanese learners, constructing a spatial mental representation during listening becomes more difficult with the increased length of the sentences. The results of correct rate and reaction time did not show significant differences among learners with a large capacity for verbal and visuo-spatial WM or those with small capacity. A possible reason for this result is that the experimental materials were not very difficult for advanced learners; therefore, a certain amount of processing resources during task execution was distributed efficiently and appropriately between verbal and visuo-spatial WM