Staggered Quantum Walks With Superconducting Microwave Resonators

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The staggered quantum walk is a model defined by the product of local operators associated with two or more independent graph tessellations. This model is versatile, encompasses several well-known discrete-time quantum walks, and inherits interesting features of the continuous-time quantum walk. We propose an implementation of the staggered quantum walk model with superconducting microwave resonators, where the required local operations are provided by the nearest neighbor interaction of the resonators coupled through superconducting quantum interference devices. The tunability of the interactions makes this system an excellent toolbox for this class of quantum walks. We focus on the one-dimensional case and discuss its generalization to a more general class known as triangle-free graphs.9514CNPq [PDJ 165941/2014-6, 303406/2015-1, 474143/2013-9]FAPESP through the Research Center in Optics and Photonics (CePOF)Faperj [26/102.350/2013]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Quantum simulation of the Anderson Hamiltonian with an array of coupled nanoresonators: delocalization and thermalization effects

The possibility of using nanoelectromechanical systems as a simulation tool for quantum many-body effects is explored. It is demonstrated that an array of electrostatically coupled nanoresonators can effectively simulate the Bose-Hubbard model without interactions, corresponding in the single-phonon regime to the Anderson tight-binding model. Employing a density matrix formalism for the system coupled to a bosonic thermal bath, we study the interplay between disorder and thermalization, focusing on the delocalization process. It is found that the phonon population remains localized for a long time at low enough temperatures; with increasing temperatures the localization is rapidly lost due to thermal pumping of excitations into the array, producing in the equilibrium a fully thermalized system. Finally, we consider a possible experimental design to measure the phonon population in the array by means of a superconducting transmon qubit coupled to individual nanoresonators. We also consider the possibility of using the proposed quantum simulator for realizing continuous-time quantum walks.Comment: Replaced with new improved version. To appear in EPJ Q

Effect of alveolar ridge preservation with PDFDBA on orthodontic tooth movement rate, formation of gingival invagination and root resorption: A randomized, controlled pilot study

Tooth extraction results in resorptive remodeling of the alveolar bone, but alveolar ridge preservation procedure maintains the original shape of the extraction socket. This may be beneficial for space closure by orthodontic tooth movement (OTM). In the current pilot study for randomized controlled clinical trial the effect of alveolar ridge preservation with partial demineralized freezedried bone allograft (PDFDBA) on OTM rate, formation of gingival invagination and root resorption was evaluated. Both mandibular first premolars of 6 patients were extracted due to orthodontic treatment. In a split-mouth study design, alveolar ridge preservation was performed on one side, while the other side served as a control and the extraction socket healed naturally. After 6 weeks of healing period, the canines were moved to the extraction site to close the extraction space. Eight weeks later, the amount of OTM was measured. After space closure, the extraction sites were examined for the presence of gingival invagination. Root resorption was evaluated on digital panoramic radiographs. Photographs were taken for documentation. There was no significant difference in OTM rate between the ridge preserved areas and naturally healed sockets. Gingival invagination formed in 5 of 6 naturally healed sockets; none of the ridge preserved areas showed formation of gingival invagination. No root resorption was observed in any of the teeth adjacent to the extraction sites. Alveolar ridge preservation with PDFDBA has no effect on the rate of OTM and root resorption but prevents formation of gingival invagination during orthodontic space closure

A Novel Method (T-Junction with a Tilted Slat) for Controlling Breakup Volume Ratio of Droplets in Micro and Nanofluidic T-Junctions

We propose a novel method for producing unequal sized droplets using a titled slat in the center of a T-junctions. In the available methods for generating unequal-sized droplets such as T-junction with valve and T-junction with a heater, the minimum breakup volume ratio that is accessible is approximately 0.3 while the system of this paper can generate droplets with the volume ratio 0.05. Therefore, the manufacturing cost of the system decreases considerably because it does not need to the consecutive breakup systems for generation of small droplets. The employed method was investigated through a numerical simulation using the volume of fluid (VOF) algorithm. The simulation results are reported for micro and nano-scaled T-junctions in various tilted slat sizes, capillary numbers (a dimensionless group describes the ratio of the inertial forces to the surface tension forces) and slat angles. Our method decreases (increases) considerably the breakup time (speed of the breakup process). For example in the case Ca=0.1 and volume ratio 0.4, dimensionless breakup time of our method and the method of T-junction with valve are 0.25 and 3.6, respectively. The results revealed that the breakup length of the nanoscale T-junction is smaller than microscale and increases by increasing the slat angle in both scales. The results demonstrated the breakup volume ratio decreases by increasing the tilted slat length. Also the breakup volume ratio minimizes in a specific slat angle. The results showed the breakup time is reduced by decreasing the slat angle. We also found that the pressure drop of the system is almost independent of the system geometry

Physiological and Molecular Aspects of Two Thymus Species Differently Sensitive to Drought Stress

Drought is one of the most important threats to plants and agriculture. Here, the effects of four drought levels (90%, 55%, 40%, and 25% field capacity) on the relative water content (RWC), chlorophyll and carotenoids levels, and mRNA gene expression of metabolic enzymes in Thymus vulgaris (as sensitive to drought) and Thymus kotschyanus (as a drought-tolerant species) were evaluated. The physiological results showed that the treatment predominantly affected the RWC, chlorophyll, and carotenoids content. The gene expression analysis demonstrated that moderate and severe drought stress had greater effects on the expression of histone deacetylase-6 (HDA-6) and acetyl-CoA synthetase in both Thymus species. Pyruvate decarboxylase-1 (PDC-1) was upregulated in Thymus vulgaris at high drought levels. Finally, succinyl CoA ligase was not affected by drought stress in either species. Data confirmed water stress is able to alter the gene expression of specific enzymes. Furthermore, our results suggest that PDC-1 expression is independent from HDA-6 and the increased expression of ACS can be due to the activation of new pathways involved in carbohydrate production