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Advances in fabrication and control of quantum dots allow the realization of metastructures that may exhibit novel electrical transport phenomena. Here, we investigate the electrical current passing through one such metastructure, a system composed of quantum dots placed at the vertices of a triangle. The wave natural of quantum particles leads to internal current circulation within the metastructure in the absence of any external magnetic field. We uncover the relation between its steady-state total current and the internal circulation. By calculating the electronic correlations in quantum transport exactly, we present phase diagrams showing where different types of current circulation can be found as a function of the correlation strength and the coupling between the quantum dots. Finally, we show that the regimes of current circulation can be further enhanced or reduced depending on the local spatial distribution of the interactions, suggesting a single-particle scattering mechanism is at play even in the strongly-correlated regime. We suggest experimental realizations of actual quantum-dot metastructures where our predictions can be directly tested.

The quantum variance of an observable is a fundamental quantity in quantum mechanics, and the variance provides additional information other than the average itself. By examining the relation between the particle-current variance $(\delta J)^2$ and the average current $J$ in both closed and open interacting fermionic systems, we show the emergence of a multi-valued Lissajous curve between $\delta J$ and $J$ due to interactions. As a closed system we considered the persistent current in a benzene-like lattice enclosing an effective magnetic flux and solved it by exact diagonalization. For the open system, the steady-state current flowing through a few lattice sites coupled to two particle reservoirs was investigated using a Lindblad equation. In both cases, interactions open a loop and change the topology of the corresponding $\delta J$-$J$ Lissajous curve, showing that this effect is model-independent. We finally discuss how the predicted phenomena can be observed in ultracold atoms, thus offering an alternative way of probing the dynamics of many-body systems.

The geometry of optical lattices can be engineered allowing the study of atomic transport along paths arranged in patterns that are otherwise difficult to probe in the solid state. A question readily accessible to atomic systems is related to the speed of propagation of matter-waves as a function of the lattice geometry. To address this issue, we have investigated theoretically the quantum transport of non-interacting and weakly-interacting ultracold fermionic atoms in several 2D optical lattice geometries. We find that the triangular lattice has a higher propagation velocity compared to the square lattice, despite supporting longer paths. The body-centered square lattice has even longer paths, nonetheless the propagation velocity is yet faster. This apparent paradox arises from the mixing of the momentum states which leads to different group velocities in quantum systems. Standard band theory provides an explanation and allows for a systematic way to search and design systems with controllable matter-wave propagation. Moreover, the presence of a flat band such as in a two-leg ladder geometry leads to a dynamical density discontinuity, which contrasts the behavior of mobile and localized atoms in quantum transport. Our predictions are realizable with present experimental capability.

Ultracold atoms provide clues to an important many-body problem regarding the dependence of Bose-Einstein condensation (BEC) transition temperature $T_c$ on interactions. However, cold atoms are trapped in harmonic potentials and theoretical evaluations of the $T_c$ shift of trapped interacting Bose gases are challenging. While previous predictions of the leading-order shift have been confirmed, more recent experiments exhibit higher-order corrections beyond available mean-field theories. By implementing two large-N based theories with the local density approximation (LDA), we extract next-order corrections of the $T_c$ shift. The leading-order large-N theory produces results quantitatively different from the latest experimental data. The leading-order auxiliary field (LOAF) theory containing both normal and anomalous density fields captures the $T_c$ shift accurately in the weak interaction regime. However, the LOAF theory shows incompatible behavior with the LDA and forcing the LDA leads to density discontinuities in the trap profiles. We present a phenomenological model based on the LOAF theory, which repairs the incompatibility and provides a prediction of the $T_c$ shift in stronger interaction regime.

Memory effects can lead to history-dependent behavior of a system, and they are ubiquitous in our daily life and have broad applications. Here we explore possibilities of generating memory effects in simple isolated quantum systems. By utilizing geometrical effects from a class of lattices supporting flat-bands consisting of localized states, memory effects could be observed in ultracold atoms in optical lattices. As the optical lattice continuously transforms from a triangular lattice into a kagome lattice with a flat band, history-dependent density distributions manifest quantum memory effects even in noninteracting systems, including fermionic as well as bosonic systems in the proper ranges of temperatures. Rapid growth in ultracold technology predicts a bright future for quantum memory-effect systems, and here two prototypical applications of geometry-induced quantum memory effects are proposed: An accelerometer recording the mechanical change rate in a coupled system and a rate-controlled memvalve where the rate of ramping the lattice potential acts as a control of the remnant density in the lattice.

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive/

Plant cells can be sensitized toward a subsequent pathogen attack by avirulent pathogens or by chemicals such as beta aminobutyric acid (BABA). This process is called priming. Using a reverse genetic approach in Arabidopsis thaliana we demonstrate that the BABA responsive L type lectin receptor kinase VI. 2 (LecRK VI.2) contributes to disease resistance against the hemibiotrophic Pseudomonas syringae and the necrotrophic Pectobacterium carotovorum bacteria. Accordingly LecRK VI.2 mRNA levels increased after bacterial inoculation or treatments with microbe associated molecular patterns (MAMPs). We also show that LecRK VI.2 is required for full activation of pattern triggered immunity (PTI); notably lecrk VI.2 1 mutants show reduced upregulation of PTI marker genes impaired callose deposition and defective stomatal closure. Overexpression studies combined with genome wide microarray analyses indicate that LecRK VI.2 positively regulates the PTI response. LecRK VI.2 is demonstrated to act upstream of mitogen activated protein kinase signaling but independently of reactive oxygen production and BOTRYTIS INDUCED KINASE1 phosphorylation. In addition complex formation between the MAMP receptor FLAGELLIN SENSING2 and its signaling partner BRASSINOSTEROID INSENSITIVE1 ASSOCIATED KINASE1 is observed in flg22 treated lecrk VI.2 1 mutants. LecRK VI.2 is also required for full BABA induced resistance and priming of PTI. Our work identifies LecRK VI.2 as a novel mediator of the Arabidopsis PTI response and provides insight into molecular mechanisms governing priming.

This study compared the agronomic properties of rice husk biochar (RHB) and wood biochar (WB) and investigated their effect on the growth rate of water spinach in a field experiment. Each biochar type was tested at 5 different rates of 4.0, 3.0, 2.0, 1.0 and 0.5 kg m3, respectively. The results detailing the growth of water spinach showed that the application of rice husk biochar improves biomass production. The WB added to soil increased the plant weight of water spinach by increasing the root size and leaf width, whereas RHB added to soil increased plant weight by increasing the stem size and leaf length of the water spinach. In addition, the stem size of water spinach was proportional to the WHC/silt ratio; whereas the root size of water spinach was proportional to the OM/OC ratio of soil. We also proposed that the working mechanism of WB and RHB in soil would be such, that the decomposition of OC in biochar-added soil to OM resulted in increased WHC and decreased silt in biochar-added soil. The decomposition of WB biochar was faster than RHB under a lower dosage amount (< 1.5 kg m3), but this trend was inversed with a higher dosage ( > 3.0 kg m3).

A new variable structure longitudinal controller is designed and analyzed for an autonomous intelligent vehicle. The proposed controller not only guarantees individual vehicle stability but also platoon stability. Moreover, the achieved platoon stability is proven to be robust with respect to vehicle parameter uncertainties and unknown time varying disturbances. Explicit transient bounds are obtained which indicate ways of choosing controller parameters for comfortable driving. 3 2431 2436 Sponsors: IEEE Computer Society ACM SIGSOFT IEE IFIP Working Group 2.9 Conference code: 42972 Cited By :11