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1.
Clin Lab ; 69(1)2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36649524

RESUMEN

BACKGROUND: Nephrin is a protein in the glomerular podocyte slit diaphragm; therefore, its presence in urine implies damage to podocytes. This study aimed to determine the usefulness of nephrin as a biomarker in maternal urine to predict preeclampsia (PE). METHODS: This prospective study included pregnant women admitted for delivery at Seoul National University Bundang Hospital from March 2019 to May 2020. Patients who had been diagnosed with PE were included, and patients without a history of underlying diseases were recruited for the control group. Pertinent clinical data were collected. Urine samples were obtained, and nephrin signaling was detected through test strips using a lateral flow assay. The point-of-care test results were compared between patients with PE and without (control group), using the exact concentration of nephrin by enzyme-linked immunosorbent assay. RESULTS: Clinical characteristics - maternal age, parity, proportion of twin pregnancies, height, weight, and cesarean delivery rate - were comparable between the PE and control groups. Nephrin signals were classified into four groups. In the PE group, signals 0, 1, 2, and 3 were found in 18.4% (9/49), 44.9% (22/49), 24.5% (12/49), and 12.2% (6/49) of participants, respectively. Results were significantly different in the control group, in which 84.3% (43/51) were found to have signal 0 (p < 0.001). CONCLUSIONS: Nephrin signaling in maternal urine could be a noninvasive and useful test for early detection of severity of PE.


Asunto(s)
Podocitos , Preeclampsia , Humanos , Embarazo , Femenino , Preeclampsia/diagnóstico , Estudios Prospectivos , Proteínas de la Membrana/metabolismo , Podocitos/metabolismo
2.
Nano Lett ; 20(9): 6299-6305, 2020 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-32787162

RESUMEN

We investigate electronic states of Se-substituted 1T-TaS2 by scanning tunneling microscopy/spectroscopy (STM/STS), where superconductivity emerges from the unique Mott-charge-density-wave (Mott-CDW) state. Spatially resolved STS measurements reveal that a pseudogap replaces the Mott gap with the CDW gaps intact. The pseudogap has little correlation with the unit-cell-to-unit-cell variation in the local Se concentration but appears globally. The correlation length of the local density of states (LDOS) is substantially enhanced at the Fermi energy and decays rapidly at high energies. Furthermore, the statistical analysis of LDOS indicates the weak multifractal behavior of the wave functions. These findings suggest a correlated metallic state induced by disorder and provide a new insight into the emerging superconductivity in two-dimensional materials.

3.
Nano Lett ; 18(9): 5432-5438, 2018 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-30063833

RESUMEN

Emergent phenomena driven by electronic reconstructions in oxide heterostructures have been intensively discussed. However, the role of these phenomena in shaping the electronic properties in van der Waals heterointerfaces has hitherto not been established. By reducing the material thickness and forming a heterointerface, we find two types of charge-ordering transitions in monolayer VSe2 on graphene substrates. Angle-resolved photoemission spectroscopy (ARPES) uncovers that Fermi-surface nesting becomes perfect in ML VSe2. Renormalization-group analysis confirms that imperfect nesting in three dimensions universally flows into perfect nesting in two dimensions. As a result, the charge-density wave-transition temperature is dramatically enhanced to a value of 350 K compared to the 105 K in bulk VSe2. More interestingly, ARPES and scanning tunneling microscopy measurements confirm an unexpected metal-insulator transition at 135 K that is driven by lattice distortions. The heterointerface plays an important role in driving this novel metal-insulator transition in the family of monolayer transition-metal dichalcogenides.

4.
Nat Mater ; 16(11): 1096-1099, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28805826

RESUMEN

Ohm's law is a fundamental paradigm in the electrical transport of metals. Any transport signatures violating Ohm's law would give an indisputable fingerprint for a novel metallic state. Here, we uncover the breakdown of Ohm's law owing to a topological structure of the chiral anomaly in the Weyl metal phase. We observe nonlinear I-V characteristics in Bi0.96Sb0.04 single crystals in the diffusive limit, which occurs only for a magnetic-field-aligned electric field (E∥B). The Boltzmann transport theory with the charge pumping effect reveals the topological-in-origin nonlinear conductivity, and it leads to a universal scaling function of the longitudinal magnetoconductivity, which completely describes our experimental results. As a hallmark of Weyl metals, the nonlinear conductivity provides a venue for nonlinear electronics, optical applications, and the development of a topological Fermi-liquid theory beyond the Landau Fermi-liquid theory.

5.
Soft Matter ; 11(40): 7932-41, 2015 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-26324955

RESUMEN

We derive an effective Maxwell-London equation for entangled polymer complexes under topological constraints, borrowing the theoretical framework from topological field theory. We find that the transverse current flux of a test polymer chain, surrounded by entangled chains, decays exponentially from its centerline position with a finite penetration depth, which is analogous to the magnetic-field decay in a superconductor (SC), referred to as the Meissner effect. Just as the mass acquirement of photons in a SC is the origin of the magnetic-field decay, the polymer obtains uncrossable intersections along the chain due to the preservation of the linking number, which restricts the deviation of the transverse polymer current in the normal direction. The underlying physics is as follows: less flexible polymers have stronger current-current correlations, giving rise to a heavier effective mass of the gauge fields and resulting in a shorter decay length. Interestingly, this picture is well incorporated within the most successful phenomenological theory of the, so called, tube model, the microscopic origins of which researchers have long pursued. The correspondence of our equation of motion to the tube model claims that the confining tube potential is a consequence of the topological constraint (linking number). The tube radius is attributed to the decay length. On increasing the effective mass (by strengthening the interaction at an uncrossable intersection or a number of intersections), the tube becomes narrower. Using this argument, the exponential decay of the chain leakage out of the tube is well understood.

6.
BMC Cardiovasc Disord ; 15: 131, 2015 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-26481213

RESUMEN

BACKGROUND: This study analyzed PWAs in patients with high Framingham risk scores to determine whether PWA is predictive of coronary artery disease (CAD) severity and percutaneous coronary intervention (PCI) treatment. METHODS: In total, 310 patients were screened due to suspected CAD; 78 were excluded due to PCI history (32), atrial fibrillation (11), or acute myocardial infarction (35). The augmentation index (AIx) was analyzed immediately before coronary angiography. PCI was performed in 73 (31.5 %) patients. RESULTS: The mean AIx, adjusted by heart rate (AIx@75) was different for each clinical diagnosis in the PCI group (stable angina, 30.6 ± 7.7 %; silent ischemia, 30.2 ± 8.6 %; unstable angina, 38.5 ± 8.5 %; p = 0.026). The 10-year estimate of CVD risk, based on the Framingham heart score, was 25.3 ± 6.5 % and the mean AIx@75 was 31.6 ± 8.5 % in the PCI group, significantly higher than in the non-PCI group (18.8 ± 10.2 %, p < 0.001; 27.2 ± 9.0 %, p = 0.006, respectively). An inverse correlation was observed between the minimal luminal area and AIx@75 (rho = -0.559, p = 0.010, n = 20). In ROC curve analysis of multivariate logistic regression model, higher HDL, medication of hypertension, and higher body mass index were associated with non-PCI and higher AIx@75 was associated with PCI (area under the curve, 0.764; 95 % CI: 0.701 to 0.819, z = 8.005; p <0.001). CONCLUSIONS: The AIx@75 seemed to reflect the clinical severity of CAD and was associated with PCI in patients with a high Framingham risk score.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Análisis de la Onda del Pulso , Anciano , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/cirugía , Femenino , Hospitales Universitarios , Humanos , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea , República de Corea , Factores de Riesgo , Índice de Severidad de la Enfermedad
7.
Biochem Biophys Res Commun ; 448(1): 114-9, 2014 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-24768638

RESUMEN

Protein precipitation is one of the most widely used methods for antigen detection and purification in biological research. We developed a reproducible aptamer-mediated magnetic protein precipitation method that is able to efficiently capture, purify and isolate the target proteins. We discovered DNA aptamers having individually high affinity and specificity against human epidermal growth factor receptor (EGFR) and human insulin receptor (INSR). Using aptamers and magnetic beads, we showed it is highly efficient technique to enrich endogenous proteins complex and is applicable to identify physiologically relevant protein-protein interactions with minimized nonspecific binding of proteins. The results presented here indicate that aptamers would be applicable as a useful and cost-effective tool to identify the presence of the particular target protein with their specific protein partners.


Asunto(s)
Precipitación Fraccionada/métodos , Proteínas/aislamiento & purificación , Técnica SELEX de Producción de Aptámeros/métodos , Antígenos CD/aislamiento & purificación , Aptámeros de Nucleótidos/metabolismo , Línea Celular Tumoral , Sulfato de Dextran , Receptores ErbB/aislamiento & purificación , Humanos , Magnetismo , Receptor de Insulina/aislamiento & purificación
8.
Sci Technol Adv Mater ; 15(6): 064401, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27877724

RESUMEN

Landau's Fermi-liquid theory is the standard model for metals, characterized by the existence of electron quasiparticles near a Fermi surface as long as Landau's interaction parameters lie below critical values for instabilities. Recently this fundamental paradigm has been challenged by the physics of strong spin-orbit coupling, although the concept of electron quasiparticles remains valid near the Fermi surface, where Landau's Fermi-liquid theory fails to describe the electromagnetic properties of this novel metallic state, referred to as Weyl metal. A novel ingredient is that such a Fermi surface encloses a Weyl point with definite chirality, referred to as a chiral Fermi surface, which can arise from breaking of either time reversal or inversion symmetry in systems with strong spin-orbit coupling, responsible for both the Berry curvature and the chiral anomaly. As a result, electromagnetic properties of the Weyl metallic state are described not by conventional Maxwell equations but by axion electrodynamics, where Maxwell equations are modified with a topological-in-origin spatially modulated [Formula: see text] term. This novel metallic state was realized recently in Bi[Formula: see text]Sb x around [Formula: see text] under magnetic fields, where the Dirac spectrum appears around the critical point between the normal semiconducting ([Formula: see text]) and topological semiconducting phases ([Formula: see text]) and the time reversal symmetry breaking perturbation causes the Dirac point to split into a pair of Weyl points along the direction of the applied magnetic field for a very strong spin-orbit coupled system. In this review article, we discuss how the topological structure of both the Berry curvature and the chiral anomaly (axion electrodynamics) gives rise to anomalous transport phenomena in [Formula: see text]Sb x around [Formula: see text] under magnetic fields, thus modifying the Drude model of Landau's Fermi liquids.

9.
Phys Rev Lett ; 111(24): 246603, 2013 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-24483684

RESUMEN

Dirac metals (gapless semiconductors) are believed to turn into Weyl metals when perturbations, which break either time reversal symmetry or inversion symmetry, are employed. However, no experimental evidence has been reported for the existence of Weyl fermions in three dimensions. Applying magnetic fields near the topological phase transition from a topological insulator to a band insulator in Bi1-xSbx we observe not only the weak antilocalization phenomenon in magnetoconductivity near zero magnetic fields (B<0.4 T), but also its upturn above 0.4 T only for E//B. This "incompatible" coexistence between weak antilocalization and "negative" magnetoresistivity is attributed to the Adler-Bell-Jackiw anomaly ("topological" E·B term) in the presence of weak antilocalization corrections.

10.
Phys Rev Lett ; 110(13): 136601, 2013 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-23581352

RESUMEN

We propose a phase diagram for Fe(x)Bi2Te3 (0≤x≤0.1) single crystals, which belong to a class of magnetically bulk-doped topological insulators. The evolution of magnetic correlations from ferromagnetic to antiferromagnetic gives rise to topological phase transitions, where the paramagnetic topological insulator of Bi2Te3 turns into a band insulator with ferromagnetic-cluster glassy behavior around x∼0.025, and it further evolves to a topological insulator with valence-bond glassy behavior, which spans over the region from x∼0.03 up to x∼0.1. This phase diagram is verified by measuring magnetization, magnetotransport, and angle-resolved photoemission spectra with theoretical discussions.

11.
Nat Commun ; 14(1): 2936, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-37217490

RESUMEN

The significant discrepancy observed between the predicted and experimental switching fields in correlated insulators under a DC electric field far-from-equilibrium necessitates a reevaluation of current microscopic understanding. Here we show that an electron avalanche can occur in the bulk limit of such insulators at arbitrarily small electric field by introducing a generic model of electrons coupled to an inelastic medium of phonons. The quantum avalanche arises by the generation of a ladder of in-gap states, created by a multi-phonon emission process. Hot-phonons in the avalanche trigger a premature and partial collapse of the correlated gap. The phonon spectrum dictates the existence of two-stage versus single-stage switching events which we associate with charge-density-wave and Mott resistive phase transitions, respectively. The behavior of electron and phonon temperatures, as well as the temperature dependence of the threshold fields, demonstrates how a crossover between the thermal and quantum switching scenarios emerges within a unified framework of the quantum avalanche.

12.
Psychiatry Investig ; 20(10): 904-911, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37899213

RESUMEN

OBJECTIVE: Providing inpatient nursing care inevitably involves night shift work. However, night shift work nurses often face psychiatric health problems such as burnout. If night shift work is an essential work type for nurses, it is necessary to select personnel suitable for night shift work or establish improvement measures such as psychiatric intervention through psychiatric evaluation. The objective of this study was to identify factors that could be interventional among factors affecting burnout in shift-working nurses. METHODS: A total of 231 night shift female nurses participated in this study. A questionnaire survey was given to assess their general characteristics. To assess burnout, the Maslach Burnout Inventory-General Survey Korean version was adopted. In addition, several mental health scales were used to identify individual psychological characteristics. To identify variables associated with the presence of burnout, odds ratios were calculated using a logistic regression model taking three dimensions of burnout as a dependent variable after adjusting for psychological and occupational factors. RESULTS: High resilience was a significant preventive factor in the three dimensions of burnout. Regarding occupational factor, the longer the duration of employment, the higher depersonalization, but the professional efficacy was good. CONCLUSION: Our results indicate that resilience and social support could be prevention factors for burnout. This study is meaningful in examining items that require active intervention and support for burnout targeting night shift nurses who are indispensable for patient care.

13.
Am J Physiol Heart Circ Physiol ; 303(8): H1001-10, 2012 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-22886417

RESUMEN

Pharmacological blockade of the ANG II type 1 receptor (AT1R) is a common therapy for treatment of congestive heart failure and hypertension. Increasing evidence suggests that selective engagement of ß-arrestin-mediated AT1R signaling, referred to as biased signaling, promotes cardioprotective signaling. Here, we tested the hypothesis that a ß-arrestin-biased AT1R ligand TRV120023 would confer cardioprotection in response to acute cardiac injury compared with the traditional AT1R blocker (ARB), losartan. TRV120023 promotes cardiac contractility, assessed by pressure-volume loop analyses, while blocking the effects of endogenous ANG II. Compared with losartan, TRV120023 significantly activates MAPK and Akt signaling pathways. These hemodynamic and biochemical effects were lost in ß-arrestin-2 knockout (KO) mice. In response to cardiac injury induced by ischemia reperfusion injury or mechanical stretch, pretreatment with TRV120023 significantly diminishes cell death compared with losartan, which did not appear to be cardioprotective. This cytoprotective effect was lost in ß-arrestin-2 KO mice. The ß-arrestin-biased AT1R ligand, TRV120023, has cardioprotective and functional properties in vivo, which are distinct from losartan. Our data suggest that this novel class of drugs may provide an advantage over conventional ARBs by supporting cardiac function and reducing cellular injury during acute cardiac injury.


Asunto(s)
Síndrome Coronario Agudo/tratamiento farmacológico , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Arrestinas/metabolismo , Cardiotónicos/farmacología , Losartán/farmacología , Oligopéptidos/farmacología , Síndrome Coronario Agudo/metabolismo , Síndrome Coronario Agudo/patología , Enfermedad Aguda , Proteínas Adaptadoras Transductoras de Señales/antagonistas & inhibidores , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Arrestinas/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Contracción Miocárdica/efectos de los fármacos , Contracción Miocárdica/fisiología , Miocardio/metabolismo , Miocardio/patología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Arrestina beta 2 , beta-Arrestinas
14.
Phys Rev Lett ; 109(14): 146601, 2012 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-23083264

RESUMEN

Material with a nontrivial topology in its electronic structure enforces the existence of helical Dirac fermionic surface states. We discover emergent topological phases in the stacked structures of topological insulator and band insulator layers where the surface Dirac fermions interact with each other with a particular helicity ordering. Using first-principles calculations and a model Lagrangian, we explicitly demonstrate that such helicity ordering occurs in real materials of ternary chalcogen compounds and determines their topological-insulating phase. Our results reveal the rich collective nature of interacting surface Dirac fermions and pave the way for utilizing topological phases for technological devices such as nonvolatile memories.

15.
Phys Rev Lett ; 109(17): 177001, 2012 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-23215215

RESUMEN

Based on the dynamical mean field theory and angle resolved photoemission spectroscopy, we have investigated the mechanism of high T(c) superconductivity in stoichiometric LiFeAs. The calculated spectrum is in excellent agreement with the measured angle resolved photoemission spectroscopy. The Fermi surface (FS) nesting, which is predicted in the conventional density functional theory method, is suppressed due to the orbital-dependent correlation effect within the dynamical mean field theory method. We have shown that such marginal breakdown of the FS nesting is an essential condition to the spin-fluctuation mediated superconductivity, while the good FS nesting in NaFeAs induces a spin density wave ground state. Our results indicate that a fully charge self-consistent description of the correlation effect is crucial in the description of the FS nesting-driven instabilities.

16.
J Korean Med Sci ; 27(10): 1162-9, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23091312

RESUMEN

Thioredoxin-1 (Trx-1) is one of important anti-oxidative molecules to overcome the oxidative stress. The aim of the present study is to investigate the clinical relationship between serum concentration of Trx-1 on the pre-percutaneous coronary intervention (prePCI) and myocardial damage amount in the patients with acute myocardial infarction with the culprit lesion in only the left anterior descending artery on coronary angiography (n = 100). Initial value of creatine kinase (CK) was 368.3 ± 531.4 U/L, and MB isoenzyme of CK (CK-MB) level was 22.92 ± 33.8 ng/mL, and cardiac specific troponin T (cTnT) level was 0.61 ± 1.6 ng/mL. Positive correlations were observed between prePCI Trx-1 level and initial CK (P = 0.005, r = 0.281), and cTnT (P < 0.001, r = 0.453), peak CK (P = 0.001, r = 0.316) in all patients, but the statistical relation was observed only in ST segment elevation myocardial infarction (STEMI) patients (P = 0.008, r = 0.329 for initial CK, P = 0.001, r = 0.498 for initial cTnT, P = 0.005, r = 0.349 for peak CK), not in Non-STEMI patients. Conclusively, we consider prePCI serum Trx-1 as a predictor for myocardial damage amount in patients with STEMI.


Asunto(s)
Infarto del Miocardio/sangre , Miocardio/patología , Tiorredoxinas/sangre , Enfermedad Aguda , Adulto , Anciano , Biomarcadores/sangre , Angiografía Coronaria , Creatina Quinasa/sangre , Forma MB de la Creatina-Quinasa/sangre , Ecocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/patología , Intervención Coronaria Percutánea , Troponina T/sangre
17.
Ann Occup Environ Med ; 34: e33, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36544884

RESUMEN

Background: Circadian rhythm disturbance caused by shift work has adverse effects on the metabolic homeostasis of the liver. Disruption of the metabolic homeostasis of the liver causes fat accumulation in the liver. The aim of this study was to investigate the correlation between shift work and non-alcoholic fatty liver disease (NAFLD) among male workers in the steel manufacturing industry of Korea. Methods: Based on medical examination data collected in June 2020, 2,511 male subjects from one steel manufacturing company in Korea were selected in total. NAFLD was evaluated using abdominal ultrasound, which was performed by two experienced radiologists. The multinomial logistic regression analysis was performed by adjusting for age, physical activity, smoking history, alcohol consumption, body mass index, waist circumference, blood pressure, blood glucose, lipidemia, liver function test, employment duration, and hepatotoxic materials exposure status. Results: Compared to daytime workers, the odds ratio (OR) of moderate-severe NAFLD in shift workers was 1.449 (95% confidence interval [CI], 1.028-2.043). Compared to daytime workers, the ORs of moderate-severe NAFLD were significantly higher for the group that engaged in total shift work for more than 20 years (OR, 2.285; 95% CI, 1.051-4.970), the group that was not allowed to sleep during night shift work (OR, 1.463; 95% CI, 1.030-2.078), and the group that consumed food during night shift work (OR, 1.580; 95% CI, 1.093-2.284). Conclusions: There was a correlation between shift work and moderate-severe NAFLD in male steel manufacturing workers. There will be a need for more research related to the correlation of shift work with steatohepatitis and cirrhosis in the future.

18.
Ann Occup Environ Med ; 33: e32, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34868602

RESUMEN

BACKGROUND: The aim of this study was to investigate the relationship between occupational exposure to various hazards and hospital admission due to endocrine diseases in Korean male firefighters. METHODS: From 2000 to 2008, former and current male firefighters registered in the Korean National Emergency Management Agency were investigated based on their hospitalized health insurance admission data for the same period. Admission data for endocrine, nutritional, and metabolic diseases were obtained from the Korean National Health Insurance Service database. Standardized admission ratio (SAR) with reference to the general population of Korean men was analyzed. RESULTS: SAR for firefighters with endocrine, nutritional, and metabolic diseases was 0.56 (95% confidence interval [CI]: 0.49-0.65), which was significantly less than that of the general population of Korean men. For those with endocrine, nutritional, and metabolic diseases, SARs for those with a history of fire suppression tasks and those without experience of fire suppression tasks were 0.58 (95% CI: 0.49-0.68) and 0.53 (95% CI: 0.40-0.70), respectively. CONCLUSIONS: The admission rate of Korean male firefighters due to endocrine, nutritional and metabolic diseases was significantly lower than that of the general Korean men population, the hazardous potential of endocrine disruptors remains an open question. Further studies of firefighters with longer follow-up are needed.

19.
Phys Rev Lett ; 104(15): 156403, 2010 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-20482002

RESUMEN

We find that the Kondo effect results in a new universality class for an antiferromagnetic (AF) quantum critical point (QCP) in the heavy fermion quantum transition, described by deconfined bosonic spinons with the dynamical exponent z=3. We show that the thermodynamics and transport of the z=3 AF QCP are consistent with the well-known non-Fermi liquid physics such as the divergent Grüneisen ratio with an exponent 2/3 and temperature-linear resistivity. We propose that the hallmark of the Kondo-driven AF QCP is a uniform spin susceptibility that diverges with an exponent 2/3, remarkably consistent with the experimental observations for YbRh2Si2.

20.
Phys Rev Lett ; 105(11): 116403, 2010 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-20867592

RESUMEN

We find that competition between random Kondo and random magnetic correlations results in a quantum phase transition from a local Fermi liquid to a spin liquid. The local charge susceptibility turns out to have exactly the same critical exponent as the local spin susceptibility, suggesting a novel duality between the Kondo singlet phase and the critical local moment state beyond the Landau-Ginzburg-Wilson symmetry breaking framework. This leads us to propose an enhanced symmetry at the local quantum critical point, described by an O(4) vector for spin and charge. The symmetry enhancement serves as a mechanism of electron fractionalization in critical impurity dynamics, where such fractionalized excitations are identified with topological excitations.

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