Effects of general non-magnetic quenched disorder on a spin-density-wave quantum critical metallic system in two spatial dimension

We investigate the effects of general non-magnetic quenched disorder on a two-dimensional spin-density-wave (SDW) quantum critical metallic system and discuss how a clean SDW non-Fermi liquid state becomes modified, based on a renormalization group (RG) method. We consider (i) all possible scattering channels by a random charge potential for fermion fields and additionally (ii) a random mass term for a SDW boson order parameter as effects of the non-magnetic quenched disorder. From the one-loop analysis, we find a weakly disordered non-Fermi liquid metallic fixed point(interacting long-range ordered fixed point) when only the random boson mass vertex is considered. However, in the general case where all disorder vertices are considered, it turns out that there is no stable fixed point and the low-energy RG flows are governed by the large random charge potential vertices especially channels in a `Direct' category with an interplay of an effective Yukawa interaction. Focusing on the physical meanings of the low-energy RG flows, we provide a detailed explanation of the one-loop results. Beyond the one-loop level, we first discuss partial two-loop corrections to the random charge potential vertices. Furthermore, we examine the possibility of different low-energy RG flows compared to that of the one-loop results by considering the two-loop corrections to the random boson mass vertex and, discuss low energy properties in relation to the random singlet phase. For physical properties, we calculate asymptotic forms of the two-point Green's functions and anomalous dimensions of the four superconducting channels in the one-loop level.Comment: Part of introduction and analysis are revise

Inhomogeneous Kondo destruction by RKKY correlations

The competition between the indirect exchange interaction (IEC) of magnetic impurities in metals and the Kondo effect gives rise to a rich quantum phase diagram, the Doniach Diagram. In disordered metals, both the Kondo temperature and the IEC are widely distributed due to the scattering of the conduction electrons from the impurity potential. Therefore, it is a question of fundamental importance, how this Doniach diagram is modified by the disorder, and if one can still identify separate phases. Recently, it has been investigated the effect of Ruderman-Kittel-Kasuya-Yosida (RKKY) correlations on the Kondo effect of two magnetic impurities, renormalizing the Kondo interaction based on the Bethe-Salpeter equation and performing the poor men's renormalization group (RG) analysis with the RKKY-renormalized Kondo coupling. In the present study, we extend this theoretical framework, allowing for different Kondo temperatures of two RKKY-coupled magnetic impurities due to different local exchange couplings and density of states. As a result, we find that the smaller one of the two Kondo temperatures is suppressed more strongly by the RKKY interaction, thereby enhancing their initial inequality. In order to find out if this relevance of inequalities between Kondo temperatures modifies the distribution of the Kondo temperature in a system of a finite density of randomly distributed magnetic impurities, we present an extension of the RKKY coupled Kondo RG equations. We discuss the implication of these results for the interplay between Kondo coupling and RKKY interaction in disordered electron systems and the Doniach diagram in disordered electron systems

Role of generic scale invariance in a Mott transition from a U(1) spin-liquid insulator to a Landau Fermi-liquid metal

We investigate the role of generic scale invariance in a Mott transition from a U(1) spin-liquid insulator to a Landau Fermi-liquid metal, where there exist massless degrees of freedom in addition to quantum critical fluctuations. Here, the Mott quantum criticality is described by critical charge fluctuations, and additional gapless excitations are U(1) gauge-field fluctuations coupled to a spinon Fermi surface in the spin-liquid state, which turn out to play a central role in the Mott transition. An interesting feature of this problem is that the scaling dimension of effective leading local interactions between critical charge fluctuations differs from that of the coupling constant between U(1) gauge fields and matter-field fluctuations in the presence of a Fermi surface. As a result, there appear dangerously irrelevant operators, which can cause conceptual difficulty in the implementation of renormalization group (RG) transformations. Indeed, we find that the curvature term along the angular direction of the spinon Fermi surface is dangerously irrelevant at this spin-liquid Mott quantum criticality, responsible for divergence of the self-energy correction term in U(1) gauge-field fluctuations. Performing the RG analysis in the one-loop level based on the dimensional regularization method, we reveal that such extremely overdamped dynamics of U(1) gauge-field fluctuations, which originates from the emergent one-dimensional dynamics of spinons, does not cause any renormalization effects to the effective dynamics of both critical charge fluctuations and spinon excitations. However, it turns out that the coupling between U(1) gauge-field fluctuations and both matter-field excitations still persists at this Mott transition, which results in novel mean-field dynamics to explain the nature of the spin-liquid Mott quantum criticality

Floristic study of Cheondeungsan Mountain in Korea

AbstractThe distribution of native plants of Cheondeungsan Mountain (807 m, N 37°05'00“–37°05'30”, E 128°00'0“–128°02'0”) in Chungcheongbuk-do was determined and the major flora were identified. During field investigations carried out from May 2011 to October 2011, 87 families, 254 genera, and 369 taxonomic groups (327 species, 4 subspecies, 33 varieties, and 5 forms) were confirmed, and the distribution of 219 taxonomic groups was discovered for the first time. The distribution of four endemic plants of Korea, including Ajuga spectabilis Nakai and Salvia chanryoenica Nakai, and that of Penthorum chinense Pursh, a Grade V specific plant species, was found. There were 20 taxa of naturalized plants at Cheondeungsan; the growth and development of plants that are harmful to the ecosystem, such as Ambrosia artemisiifolia L., Ambrosia trifida L., Eupatorium rugosum Houtt., and Aster pilosus Willd., was observed around the forest paths and lowlands

Patient Perception of Natural Orifice Transluminal Endoscopic Surgery in an Endoscopy Screening Program in Korea

Purpose Natural orifice transluminal endoscopic surgery (NOTES) is a new method of accessing intracavitary organs in order to minimize pain by avoiding incisions in the body wall. The aim of this study is to determine patients' acceptance of NOTES in Korea and to compare their views about laparoscopic surgery and NOTES for benign and malignant diseases. Materials and Methods The target number of total subjects was calculated to be 540. The subjects were classified into 18 sub-groups based on age groups, gender, and history of prior surgery. The questionnaire elicited information about demographic characteristics, medical check-ups, diseases, endoscopic and surgical histories, marital status and childbirth, the acceptance of NOTES, and the preferred routes for NOTES. In addition, the subjects chose laparoscopic surgery or NOTES for a hypothetical cholecystectomy and rectal cancer surgery, and responded to questions regarding the acceptable complication rate of NOTES, the appropriate cost of NOTES, and the reason(s) why they did not select NOTES. Results: 486 of 540 patients (90.0%) who agreed to participate in this study completed the questionnaire. NOTES was preferred by the following patients: elderly; a history of treatment due to a disease; having regular check-ups; and a history of an endoscopic procedure (p<0.05). The most preferred route for NOTES was the stomach (67.1%). Eighty-four percent of the patients choosing NOTES responded that the complication rate of the new surgical method should be the same or lower than laparoscopic surgery. Vague anxiety over a new surgical method was the most common reason why NOTES was not selected in benign and malignant diseases (64% and 73%), respectively. Conclusion: Patients appear to be interested in the potential benefits of NOTES and would embrace it if their concerns about safety are met. We believe that qualified surgical endoscopists can meet these safety concerns, and that NOTES development has the potential to flourish

Standardization of Terminology in Laboratory Medicine II

Standardization of medical terminology is essential in data transmission between health care institutes and in maximizing the benefits of information technology. The purpose of this study was to standardize medical terms for laboratory observations. During the second year of the study, a standard database of concept names for laboratory terms that covered those used in tertiary health care institutes and reference laboratories was developed. The laboratory terms in the Logical Observation Identifier Names and Codes (LOINC) database were adopted and matched with the electronic data interchange (EDI) codes in Korea. A public hearing and a workshop for clinical pathologists were held to collect the opinions of experts. The Korean standard laboratory terminology database containing six axial concept names, components, property, time aspect, system (specimen), scale type, and method type, was established for 29,340 test observations. Short names and mapping tables for EDI codes and UMLS were added. Synonym tables were prepared to help match concept names to common terms used in the fields. We herein described the Korean standard laboratory terminology database for test names, result description terms, and result units encompassing most of the laboratory tests in Korea