Continuous Measurement of a Non-Markovian Open Quantum System

Continuous quantum measurement is the backbone of various methods in quantum control, quantum metrology, and quantum information. Here, we present a generalized formulation of dispersive measurement of a complex quantum systems. We describe the complex system as an open quantum system that is strongly coupled to a non-Markovian environment, enabling the treatment of a broad variety of natural or engineered complex systems. The system is monitored via a probe resonator coupled to a broadband (Markovian) reservoir. Based on this model, we derive a formalism of Stochastic Hierarchy Equations of Motion (SHEM) describing the decoherence dynamics of the system conditioned on the measurement record. Furthermore, we demonstrate a spectroscopy method based on weak quantum measurement to reveal the non-Markovian nature of the environment, which we term weak spectroscopy.Comment: Published version, the section on continuous state tomography will be published in a separate manuscrip

Gating of high-mobility InAs metamorphic heterostructures

We investigate the performance of gate-defined devices fabricated on high mobility InAs metamorphic heterostructures. We find that heterostructures capped with In$_{0.75}$Ga$_{0.25}$As often show signs of parallel conduction due to proximity of their surface Fermi level to the conduction band minimum. Here, we introduce a technique that can be used to estimate the density of this surface charge that involves cool-downs from room temperature under gate bias. We have been able to remove the parallel conduction under high positive bias, but achieving full depletion has proven difficult. We find that by using In$_{0.75}$Al$_{0.25}$As as the barrier without an In$_{0.75}$Ga$_{0.25}$As capping, a drastic reduction in parallel conduction can be achieved. Our studies show that this does not change the transport properties of the quantum well significantly. We achieved full depletion in InAlAs capped heterostructures with non-hysteretic gating response suitable for fabrication of gate-defined mesoscopic devices

Locally Optimal Control of Quantum Systems with Strong Feedback

For quantum systems with high purity, we find all observables that, when continuously monitored, maximize the instantaneous reduction in the von Neumann entropy. This allows us to obtain all locally optimal feedback protocols with strong feedback, and explicit expressions for the best such protocols for systems of size N <= 4. We also show that for a qutrit the locally optimal protocol is the optimal protocol for a given range of control times, and derive an upper bound on all optimal protocols with strong feedback.Comment: 4 pages, Revtex4. v2: published version (some errors corrected

Study of genetic structure of Rutilus frisii kutum in Golestan province coastal waters using microsatellite markers

To determine the genetic diversity of Rutilus frisii kutum, 25 samples were collected from Gharesou and Gorgan-rud rivers in April 2008. The genomic DNA was extracted from the caudal fin using phenol- chloroform method and investigated with 10 microsatellite loci. All the 10 investigated loci were polymorphic and showed variability in the two populations of the rivers. The mean number of allele per locus at population level and the observed heterozygosity ranged from 4 to 13 and 0.22 to 1.00, respectively. The FST value between populations was 0.014 (P<0.05), and the analysis of genetic variation distribution indicated a very high within population variation (99%) while among population variation is low (1%). Highly significant deviation from hardy-Weinberg equilibrium was observed in both populations which can be attributed either to the presence of null alleles or to the genetic bottleneck. The results indicated a high level of genetic variation in this species and we concluded that there is more than one population of Rutilus frisii kutum in Golestan coastal waters

Inhibitory impacts of natural antioxidants (ascorbic and citric acid) and vacuum packaging on lipid oxidation in frozen Persian sturgeon fillets

This study was aimed to investigate effects of aqueous citric acid (CA) and ascorbic acid (AA) on lipid oxidation in comparison with effect of vacuum packaging in order to find better treatment to delay improper changes in the Persian sturgeon (Acipenser persicus) fillets during frozen storage due to lipid oxidation. In this study traditional packaging, vacuum packaging, ascorbic acid solution (0.5 %) and citric acid solution (0.5 %) were considered as treatments. Rancidity development was measured by several biochemical indicators including Free Fatty Acids, Peroxide values and Thiobarbituric acid. Also pH, expressible moisture and sensory properties were measured during 6 months storage. Results showed that free fatty acid (FFA), primary and secondary oxidation products of control samples were significantly higher than those in other treatments (p<0.05). Also, expressible moisture and pH value of treated samples were significantly lower than those in control (p<0.05). However both antioxidants (AA and CA) extended shelf life of frozen fillets but rancidity development in CA treated samples was higher than other samples during storage. Results showed that all three treatments had significant effect on delaying lipid oxidation (p<0.05) but usage of AA and vacuum packaging had the best effect on delaying lipid oxidation and increasing shelf-life of fillets (p<0.05) . Thus the employment of AA and vacuum packaging alone or in combination with other protective strategies is recommended

Anisotropic low-temperature piezoresistance in (311)A GaAs two-dimensional holes

We report low-temperature resistance measurements in a modulation-doped, (311)A GaAs two-dimensional hole system as a function of applied in-plane strain. The data reveal a strong but anisotropic piezoresistance whose magnitude depends on the density as well as the direction along which the resistance is measured. At a density of $1.6\times10^{11}$ cm$^{-2}$ and for a strain of about $2\times10^{-4}$ applied along [01$\bar{1}$], e.g., the resistance measured along this direction changes by nearly a factor of two while the resistance change in the [$\bar{2}$33] direction is less than 10% and has the opposite sign. Our accurate energy band calculations indicate a pronounced and anisotropic deformation of the heavy-hole dispersion with strain, qualitatively consistent with the experimental data. The extremely anisotropic magnitude of the piezoresistance, however, lacks a quantitative explanation.Comment: 4 pages. Submitted to Applied Physics Letter

The influence of the centre bow and wet-deck geometry on motions of wave piercing catamarans

The effects of tunnel height and centre bow length on the motions of a 112-m wave-piercer catamaran with an above-water centre bow were investigated through model tests. Five alternative centre bow configurations were considered, and multiple series of model tests were conducted in regular head sea waves. The results showed that both heave and pitch increased over a wide range of wave encounter frequency as the wet-deck height of the catamaran model increased. However, increasing the length of the centre bow showed an increase in the pitch but a decrease in the heave for a limited range of wave encounter frequency near the heave and pitch resonance frequencies of the catamaran model. The positions of minimum vertical displacement were found to be aft of the longitudinal centre of gravity, between 20% and 38% of the overall length from the transom. Increase in the wet-deck height and consequently the archway clearance between the main hulls and centre bow also resulted in an increase in the vertical displacement relative to the undisturbed water surface in the centre bow area. The results also indicated the vulnerability to wet-deck slamming for the different bow and wet-deck designs

Fillet quality grading of common carp (Cyprinus carpio) by fish size using mathematical equations

Quality grading and nutrition value determination of fish are nowadays necessary for aquatic processing. The present study was conducted to investigate a new, applied and cheap method of fillet quality grading for common carp (Cyprinus carpio) using fish size, based on mathematical equations. For this reason, 61 specimens of cultured market size carp were used and after filleting, their moisture, lipid, protein, energy and ash content were measured. Then, the relationships between proximate composition components of fillet and fillet length were studied. Results showed that there is an inverse linear regression relationship between logarithm of moisture content and logarithm of fish length (P0.05). Regarding the relationship between proximate composition of cultured carp fillets and fillet length machine fish sorting based on fish length and grading of moisture, lipid and energy content is feasible. We also found it feasible to determine type of processing and proximate composition of the prepared common carp

Capability framework for sustainable manufacturing of sports apparel and footwear

The sporting goods sector is characterized by large volumes of production, high levels of consumption and short product life cycles resulting in high disposal rates and waste. Manufacturing of sports products is distributed globally through tier-based supply chains and complex logistics systems. Companies within such supply chains have different levels of capability in sustainable manufacturing, which impacts on the sustainability of the overall business. Reducing environmental impacts is of particular concern for companies at present, due to heightened requirements for the reduction of energy and water consumption, waste and greenhouse gas (GHG) emissions. This article describes outcomes of a research project conducted in collaboration with a global sporting goods manufacturer that focused on the development of relevant capabilities across their supply chain for sustainable manufacturing of sports apparel and footwear. The article presents the developed sustainable manufacturing framework and capability assessment results obtained for selected companies within the supply chain of this global manufacturer in Asia

Inhibitory effect of citric acid on rancidity of frozen catfish (Silurus glanis)fillets

The effect of aqueous solution of citric acid (CA) on the lipid stability of the European catfish (Silurus glanis) fillets during frozen storage (up to 6 months) was investigated. Rancidity development was measured by several biochemical indices (free fatty acids, peroxides and TBA) and complemented by the measurement of expressible moisture and sensory evaluation (flesh odor, consistency and flesh appearance). The CA treatment led to some lower free fatty acids (6.43% oleic acid in total lipid at month 6), peroxides (7.98meq oxygen/kg lipids, at month 6) and secondary compounds formation (2.16mg malondialdehyde/kg fish sample). Lower peroxide, thiobarbituric acid-reactive substance (TBA), free fatty acids (during 0,3 and 6 months frozen storage), and expressible moisture (month 6) values were obtained from CA-treated fish fillets than the untreated (blank control) ones (P<0.05)