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<jats:p>In this paper we investigate two techniques for single event effect (SEE) mitigation by using back junction and p<jats:sup>+</jats:sup> buffer layer in non-deep trench isolation (DTI) domestic silicon–germanium heterojunction bipolar transistors (SiGe HBTs) based on technology computer aided design (TCAD) simulation. The effectiveness of the two mitigation techniques and the influence of various structure parameters are investigated. Simulation results indicate that the two techniques are more effective in reducing collector charge collection induced by heavy ions striking at positions outside the collector–substrate (C–S) junction where charge collection is dominated by diffusion. By properly adjusting the parameters, charge collection of events outside the C–S junction can be reduced by more than an order of magnitude, while charge collection of events in the device center is halved without affecting the direct current (DC) and alternating current (AC) characteristics of the SiGe HBTs.</jats:p>

<jats:p>10-kV 4H–SiC p-channel insulated gate bipolar transistors (IGBTs) are designed, fabricated, and characterized in this paper. The IGBTs have an active area of 2.25 mm<jats:sup>2</jats:sup> with a die size of 3 mm × 3 mm. A step space modulated junction termination extension (SSM-JTE) structure is introduced and fabricated to improve the blocking performance of the IGBTs. The SiC p-channel IGBTs with SSM-JTE termination exhibit a leakage current of only 50 nA at −10 kV. To improve the on-state characteristics of SiC IGBTs, the hexagonal cell (H-cell) structure is designed and compared with the conventional interdigital cell (I-cell) structure. At an on-state current of 50 A/cm<jats:sup>2</jats:sup>, the voltage drops of I-cell IGBT and H-cell IGBT are 10.1 V and 8.3 V respectively. Meanwhile, on the assumption that the package power density is 300 W/cm<jats:sup>2</jats:sup>, the maximum permissible current densities of the I-cell IGBT and H-cell IGBT are determined to be 34.2 A/cm<jats:sup>2</jats:sup> and 38.9 A/cm<jats:sup>2</jats:sup> with forward voltage drops of 8.8 V and 7.8 V, respectively. The differential specific on-resistance of I-cell structure and H-cell structure IGBT are <jats:inline-formula> <jats:tex-math> <?CDATA $72.36\,{\rm{m}}{\rm{\Omega }}\cdot {\mathrm{cm}}^{2}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>72.36</mml:mn> <mml:mspace width="0.25em" /> <mml:mi mathvariant="normal">m</mml:mi> <mml:mi mathvariant="normal">Ω</mml:mi> <mml:mo>·</mml:mo> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_068504_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math> <?CDATA $56.92\,{\rm{m}}{\rm{\Omega }}\cdot {\mathrm{cm}}^{2}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>56.92</mml:mn> <mml:mspace width="0.25em" /> <mml:mi mathvariant="normal">m</mml:mi> <mml:mi mathvariant="normal">Ω</mml:mi> <mml:mo>·</mml:mo> <mml:msup> <mml:mrow> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_6_068504_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, respectively. These results demonstrate that H-cell structure silicon carbide IGBT with SSM-JTE is a promising candidate for high power applications.</jats:p>

<jats:p>DNA–RNA hybrid (DRH) plays important roles in many biological processes. Here, we use a thermodynamic theory to analyze the free energy and unpeeling properties of the overstretching transition for the DRH molecule and compare the results with double-helix DNA. We report that the RNA strand of DRH is easier to get unpeeled than the DNA strand while the difficulty in unpeeling the double helix DNA lies in between. We also investigate the sequence effect, such as GC content and purine content, on the properties of unpeeling the DRH. Further, to study the temperature effect, the force-temperature phase diagram of DRH and DNA are calculated and compared. Finally, using a kinetic model, we calculate the force–extension curves in the DRH stretching and relaxation process under different pulling rates and temperatures. Our results show that both pulling rate and temperature have important influences on the stretching and relaxation kinetics of unpeeling the DRH. Putting all these results together, our work provides a comprehensive view of both the thermodynamics and kinetics in DRH overstretching.</jats:p>

<jats:p>The emergence of Event-based Social Network (EBSN) data that contain both social and event information has cleared the way to study the social interactive relationship between the virtual interactions and physical interactions. In existing studies, it is not really clear which factors affect event similarity between online friends and the influence degree of each factor. In this study, a multi-layer network based on the Plancast service data is constructed. The the user’s events belongingness is shuffled by constructing two null models to detect offline event similarity between online friends. The results indicate that there is a strong correlation between online social proximity and offline event similarity. The micro-scale structures at multi-levels of the Plancast online social network are also maintained by constructing 0<jats:italic>k</jats:italic>–3<jats:italic>k</jats:italic> null models to study how the micro-scale characteristics of online networks affect the similarity of offline events. It is found that the assortativity pattern is a significant micro-scale characteristic to maintain offline event similarity. Finally, we study how structural diversity of online friends affects the offline event similarity. We find that the subgraph structure of common friends has no positive impact on event similarity while the number of common friends plays a key role, which is different from other studies. In addition, we discuss the randomness of different null models, which can measure the degree of information availability in privacy protection. Our study not only uncovers the factors that affect offline event similarity between friends but also presents a framework for understanding the pattern of human mobility.</jats:p>

<jats:p>We present the entanglement measures of a tetrapartite W-class entangled system in a noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied. Two cases are considered. First, when one qubit has uniform acceleration whilst the other three remain stationary. Second, when two qubits have nonuniform accelerations and the others stay inertial. The 1–1 tangle, 1–3 tangle, and whole entanglement measurements <jats:inline-formula> <jats:tex-math><?CDATA ${\pi }_{4}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>π</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070301_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA ${{\rm{\Pi }}}_{4}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">Π</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070301_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, are studied and illustrated with graphics through their dependence on the acceleration parameter <jats:italic>r</jats:italic> <jats:sub>d</jats:sub> for the first case and <jats:italic>r</jats:italic> <jats:sub>c</jats:sub> and <jats:italic>r</jats:italic> <jats:sub>d</jats:sub> for the second case. It is found that the negativities (1–1 tangle and 1–3 tangle) and <jats:italic>π</jats:italic>-tangle decrease when the acceleration parameter <jats:italic>r</jats:italic> <jats:sub>d</jats:sub> or in the second case <jats:italic>r</jats:italic> <jats:sub>c</jats:sub> and <jats:italic>r</jats:italic> <jats:sub>d</jats:sub> increase, remaining a nonzero entanglement in the majority of the results. This means that the system will be always entangled except for special cases. It is shown that only the 1–1 tangle for the first case vanishes at infinite accelerations, but for the second case the 1–1 tangle disappears completely when <jats:inline-formula> <jats:tex-math><?CDATA $r\gt 0.472473$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>r</mml:mi> <mml:mo>&gt;</mml:mo> <mml:mn>0.472473</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070301_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>. An analytical expression for the von Neumann information entropy of the system is found and we note that it increases with the acceleration parameter.</jats:p>

<jats:p>We consider a SU(3) spin–orbit coupled Bose–Einstein condensate confined in a harmonic plus quartic trap. The ground-state wave functions of such a system are obtained by minimizing the Gross–Pitaevskii energy functional, and the effects of the spin-dependent interaction and spin–orbit coupling are investigated in detail. For the case of ferromagnetic spin interaction, the SU(3) spin–orbit coupling induces a threefold-degenerate plane wave ground state with nontrivial spin texture. For the case of antiferromagnetic spin interaction, the system shows phase separation for weak SU(3) spin–orbit coupling, where three discrete minima with unequal weights in momentum space are selected, while hexagonal honeycomb lattice structure for strong SU(3) SOC, where three discrete minima with equal weights are selected.</jats:p>

<jats:p>For an open quantum system containing two qubits under homodyne-based feedback control, we investigate the dynamical behaviors of quantum-memory-assisted entropic uncertainty. Moreover, we analyze the influence of feedback modes and coefficients on the entropic uncertainty. Numerical investigations show that the memory qubit should be placed in a non-dissipative channel if the single dissipative channel condition can be chosen, which helps reduce the entropic uncertainty of the system. For the homodyne feedback control <jats:inline-formula> <jats:tex-math><?CDATA $F=\lambda {\sigma }_{x}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>F</mml:mi> <mml:mo>=</mml:mo> <mml:mi>λ</mml:mi> <mml:msub> <mml:mrow> <mml:mi>σ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070303_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> (or <jats:inline-formula> <jats:tex-math><?CDATA $F=\lambda {\sigma }_{y})$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>F</mml:mi> <mml:mo>=</mml:mo> <mml:mi>λ</mml:mi> <mml:msub> <mml:mrow> <mml:mi>σ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070303_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, due to different roles of the entangled qubits A and B, when they are subject to feedback control with different feedback coefficients <jats:italic>λ</jats:italic>, the exchange of feedback coefficients will cause variations of the entropic uncertainty. When the feedback coefficient corresponding to the memory qubit B is larger (<jats:inline-formula> <jats:tex-math><?CDATA ${\lambda }_{{\rm{B}}}\gt {\lambda }_{{\rm{A}}})$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">B</mml:mi> </mml:mrow> </mml:msub> <mml:mo>&gt;</mml:mo> <mml:msub> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">A</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070303_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>, the steady value of the entropic uncertainty will be small, which is conducive to enhancing the robustness of the system. However, for the feedback control <jats:inline-formula> <jats:tex-math><?CDATA $F=\lambda {\sigma }_{z}$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>F</mml:mi> <mml:mo>=</mml:mo> <mml:mi>λ</mml:mi> <mml:msub> <mml:mrow> <mml:mi>σ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>z</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070303_ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>, the difference between the feedback coefficients has no effect on the steady values of the entropic uncertainty.</jats:p>

<jats:p>Recently, Tavakoli <jats:italic>et al</jats:italic>. proposed a self-testing scheme in the prepare-and-measure scenario, showing that self-testing is not necessarily based on entanglement and violation of a Bell inequality [<jats:italic>Phys. Rev. A</jats:italic> <jats:bold> <jats:italic>98</jats:italic> </jats:bold> <jats:italic>062307 (2018)</jats:italic>]. They realized the self-testing of preparations and measurements in an <jats:inline-formula> <jats:tex-math><?CDATA $N\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>N</mml:mi> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> (<jats:inline-formula> <jats:tex-math><?CDATA $N\ge 2$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>N</mml:mi> <mml:mo>≥</mml:mo> <mml:mn>2</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn4.gif" xlink:type="simple" /> </jats:inline-formula>) random access code (RAC), and provided robustness bounds in a <jats:inline-formula> <jats:tex-math><?CDATA $2\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>2</mml:mn> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn5.gif" xlink:type="simple" /> </jats:inline-formula> RAC. Since all <jats:inline-formula> <jats:tex-math><?CDATA $N\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>N</mml:mi> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn6.gif" xlink:type="simple" /> </jats:inline-formula> RACs with shared randomness are combinations of <jats:inline-formula> <jats:tex-math><?CDATA $2\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>2</mml:mn> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn7.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $3\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>3</mml:mn> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn8.gif" xlink:type="simple" /> </jats:inline-formula> RACs, the <jats:inline-formula> <jats:tex-math><?CDATA $3\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>3</mml:mn> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn9.gif" xlink:type="simple" /> </jats:inline-formula> RAC is just as important as the <jats:inline-formula> <jats:tex-math><?CDATA $2\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>2</mml:mn> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn10.gif" xlink:type="simple" /> </jats:inline-formula> RAC. In this paper, we find a set of preparations and measurements in the <jats:inline-formula> <jats:tex-math><?CDATA $3\to 1$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>3</mml:mn> <mml:mo>→</mml:mo> <mml:mn>1</mml:mn> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_7_070304_ieqn11.gif" xlink:type="simple" /> </jats:inline-formula> RAC, and use them to complete the robustness self-testing analysis in the prepare-and-measure scenario. The method is robust to small but inevitable experimental errors.</jats:p>

<jats:p>When the finite difference time domain (FDTD) method is used to solve electromagnetic scattering problems in Schwarzschild space-time, the Green functions linking source/observer to every surface element on connection/output boundary must be calculated. When the scatterer is electrically extended, a huge amount of calculation is required due to a large number of surface elements on the connection/output boundary. In this paper, a method for reducing the calculation workload of Green function is proposed. The Taylor approximation is applied for the calculation of Green function. New transport equations are deduced. The numerical results verify the effectiveness of this method.</jats:p>

<jats:p>For a two-dimensional ultra-cold Fermi superfluid with an effective static magnetic impurity, we theoretically investigated the variation of the Yu–Shiba–Rusinov (YSR) bound state in the Bardeen–Cooper–Schrieffer (BCS) to Bose–Einstein condensation (BEC) crossover regime. Within the framework of mean-field theory, analytical results of the YSR bound state energy were obtained as a function of the interaction parameters. First, when the background Fermi superfluid system stays in the weakly interacting BCS regime, we found that the YSR bound state energy is linearly dependent on the gap parameter with its coefficient slightly different from previous results. Second, we discovered re-entrance phenomena for the YSR state and an upper bound of the strength of the interaction between the paired atoms. By carefully analyzing the bound state energy as a function of the interaction parameters, we obtained a phase diagram showing the existence of the YSR state. Finally, we concluded that the re-entrance phenomena and the critical point can be easily experimentally detected through measurement of radio-frequency spectroscopy and density of states using current experimental techniques.</jats:p>