Strange metal in paramagnetic heavy-fermion Kondo lattice: Dynamical large-N fermionic multi-channel approach

The mechanism of strange metal (SM) with unconventional charge transport near magnetic phase transitions has become an outstanding open problem in correlated electron systems. Recently, an exotic quantum critical SM phase was observed in paramagnetic frustrated heavy-fermion materials near Kondo breakdown. We establish a controlled theoretical framework to this issue via a dynamical large-N fermionic multichannel approach to the two-dimensional Kondo-Heisenberg lattice model, where KB transition separates a heavy-Fermi liquid from fermionic spin-liquid state. With Kondo fluctuations being fully considered, we find a distinct SM behavior with quasi-linear-in-temperature scattering rate associated with KB. When particle-hole symmetry is present, signatures of a critical spin-liquid SM phase as $T \rightarrow 0$ are revealed with $\omega/T$ scaling extended to a wide range. We attribute these features to the interplay of critical bosonic charge (Kondo) fluctuations and gapless fermionic spinons. The implications of our results for the experiments are discussed.Comment: 6 pages, 4 figure

Supply Chain Efficiency Analysis: A Theoretical Approach

We divide the supply chain into a central control system (CCS) case and a decentralized control system (DCS) case, and compare the supply chain efficiency with both the CCS case and the DCS case.  We find that the supply chain efficiency of a capital-intensive industry is better under the CCS case than under the DCS case.  Under the CCS case, the maximized supply chain efficiency can be reached by choosing either the lowest price that the upstream firm is willing to receive or the highest price that the downstream firm is willing to pay for intermediate goods

Linear Displacement and Straightness Measurement by Fabry-Perot Interferometer Integrated with an Optoelectronic Module

This research develops a three degrees of freedom (DOF) measurement system by integrating Fabry-Perot interferometer and photoelectronic inspection module to determine linear displacement, horizontal and vertical straightness geometric error parameters simultaneously. The interferometer and the photoelectronic inspection module in a three DOF measurement system share the same light source, and the two structures are used to measure linear displacement and straightness errors. The experimental results are utilized to calculate the relevant error parameters according to ISO standards and numerical analysis. They show that after the machine error compensation, the positioning deviation of the system is reduced from 55 μm to 19 μm, corresponding to the reduction of 65%. The accuracy is promoted from 65 μm to 31 μm, about the improvement of 52%. The horizontal and vertical straightness errors of the machine are 4.30 μm and 5.71 μm respectively

Leveling Maintenance Mechanism by Using the Fabry-Perot Interferometer with Machine Learning Technology

This study proposes a method for maintaining parallelism of the optical cavity of a laser interferometer using machine learning. The Fabry-Perot interferometer is utilized as an experimental optical structure in this research due to its advantage of having a brief optical structure. The supervised machine learning method is used to train algorithms to accurately classify and predict the tilt angle of the plane mirror using labeled interference images. Based on the predicted results, stepper motors are fixed on a plane mirror that can automatically adjust the pitch and yaw angles. According to the experimental results, the average correction error and standard deviation in 17-grid classification experiment are 32.38 and 11.21 arcseconds, respectively. In 25-grid classification experiment, the average correction error and standard deviation are 19.44 and 7.86 arcseconds, respectively. The results show that this parallelism maintenance technology has essential for the semiconductor industry and precision positioning technology

Search for quantum dimer phases and transitions in a frustrated spin ladder

A two-leg spin-1/2 ladder with diagonal interactions is investigated numerically. We focus our attention on the possibility of columnar dimer phase, which was recently predicted based on a reformulated bosonization theory. By using density matrix renormalization group technique and exact diagonalization method, we calculate columnar dimer order parameter, spin correlation on a rung, string order parameters, and scaled excitation gaps. Carefully using various finite-size scaling techniques, our results show no support for the existence of columnar dimer phase in the spin ladder under consideration.Comment: 5 pages, 4 figures. To be published in Phys. Rev.

Pneumocystis jiroveci Pneumonia in Patients with Non-Hodgkin's Lymphoma Receiving Chemotherapy Containing Rituximab

AbstractRituximab enhances treatment efficacy of B-lineage lymphoma by targeting CD20+ B-cells. Such target therapies may compromise the immune system and render patients susceptible to opportunistic infections. We report 2 cases of lymphoma complicated with Pneumocystis jiroveci (previously known as P. carinii) pneumonia (PCP) while being treated with rituximab-containing chemotherapy regimens. In both cases, PCP developed during the neutropenic period. With timely diagnosis and proper management, both were treated successfully. We searched the literature and found that such opportunistic infection occurred only infrequently in lymphoma patients, and it has not been reported in the large-scale clinical trials of rituximab. Such cases demonstrate the importance of taking PCP into diagnostic consideration in lymphoma patients receiving similar therapies

Disordered Fe vacancies and superconductivity in potassium-intercalated iron selenide (K2-xFe4+ySe5)

The parent compound of an unconventional superconductor must contain unusual correlated electronic and magnetic properties of its own. In the high-Tc potassium intercalated FeSe, there has been significant debate regarding what the exact parent compound is. Our studies unambiguously show that the Fe-vacancy ordered K2Fe4Se5 is the magnetic, Mott insulating parent compound of the superconducting state. Non-superconducting K2Fe4Se5 becomes a superconductor after high temperature annealing, and the overall picture indicates that superconductivity in K2-xFe4+ySe5 originates from the Fe-vacancy order to disorder transition. Thus, the long pending question whether magnetic and superconducting state are competing or cooperating for cuprate superconductors may also apply to the Fe-chalcogenide superconductors. It is believed that the iron selenides and related compounds will provide essential information to understand the origin of superconductivity in the iron-based superconductors, and possibly to the superconducting cuprates